diff --git a/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp b/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
--- a/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
+++ b/libcxx/test/std/strings/basic.string.hash/enabled_hashes.pass.cpp
@@ -26,7 +26,7 @@
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
     test_hash_enabled_for_type<std::wstring>();
 #endif
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test_hash_enabled_for_type<std::u8string>();
 #endif
     test_hash_enabled_for_type<std::u16string>();
diff --git a/libcxx/test/std/strings/basic.string.hash/strings.pass.cpp b/libcxx/test/std/strings/basic.string.hash/strings.pass.cpp
--- a/libcxx/test/std/strings/basic.string.hash/strings.pass.cpp
+++ b/libcxx/test/std/strings/basic.string.hash/strings.pass.cpp
@@ -44,7 +44,7 @@
 int main(int, char**)
 {
     test<std::string>();
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test<std::u8string>();
 #endif
     test<std::u16string>();
diff --git a/libcxx/test/std/strings/basic.string.literals/literal.pass.cpp b/libcxx/test/std/strings/basic.string.literals/literal.pass.cpp
--- a/libcxx/test/std/strings/basic.string.literals/literal.pass.cpp
+++ b/libcxx/test/std/strings/basic.string.literals/literal.pass.cpp
@@ -13,7 +13,7 @@
 
 #include "test_macros.h"
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     typedef std::u8string u8string;
 #else
     typedef std::string   u8string;
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign2.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign2.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign2.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign2.pass.cpp
@@ -17,7 +17,7 @@
 
 #include "test_macros.h"
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
 constexpr bool test_constexpr()
 {
     char8_t c = u'1';
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign3.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign3.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign3.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/assign3.pass.cpp
@@ -21,7 +21,7 @@
 
 TEST_CONSTEXPR_CXX20 bool test()
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     char8_t s2[3] = {0};
     assert(std::char_traits<char8_t>::assign(s2, 3, char8_t(5)) == s2);
     assert(s2[0] == char8_t(5));
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/compare.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/compare.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/compare.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/compare.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
 constexpr bool test_constexpr()
 {
     return std::char_traits<char8_t>::compare(u8"123", u8"223", 3) < 0
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/copy.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/copy.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/copy.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/copy.pass.cpp
@@ -21,7 +21,7 @@
 
 TEST_CONSTEXPR_CXX20 bool test()
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     char8_t s1[] = {1, 2, 3};
     char8_t s2[3] = {0};
     assert(std::char_traits<char8_t>::copy(s2, s1, 3) == s2);
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eof.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eof.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eof.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eof.pass.cpp
@@ -20,7 +20,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     std::char_traits<char8_t>::int_type i = std::char_traits<char8_t>::eof();
     ((void)i); // Prevent unused warning
 #endif
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq.pass.cpp
@@ -20,7 +20,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     assert( std::char_traits<char8_t>::eq(u8'a', u8'a'));
     assert(!std::char_traits<char8_t>::eq(u8'a', u8'A'));
 #endif
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq_int_type.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq_int_type.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq_int_type.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/eq_int_type.pass.cpp
@@ -20,7 +20,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     assert( std::char_traits<char8_t>::eq_int_type(u8'a', u8'a'));
     assert(!std::char_traits<char8_t>::eq_int_type(u8'a', u8'A'));
     assert(!std::char_traits<char8_t>::eq_int_type(std::char_traits<char8_t>::eof(), u8'A'));
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/find.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/find.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/find.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/find.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
 constexpr bool test_constexpr()
 {
     constexpr const char8_t *p = u8"123";
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/length.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/length.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/length.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/length.pass.cpp
@@ -18,7 +18,7 @@
 
 #include "test_macros.h"
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
 constexpr bool test_constexpr()
 {
     return std::char_traits<char8_t>::length(u8"") == 0
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/lt.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/lt.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/lt.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/lt.pass.cpp
@@ -20,7 +20,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     assert(!std::char_traits<char8_t>::lt(u8'a', u8'a'));
     assert( std::char_traits<char8_t>::lt(u8'A', u8'a'));
 #endif
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/move.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/move.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/move.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/move.pass.cpp
@@ -21,7 +21,7 @@
 
 TEST_CONSTEXPR_CXX20 bool test()
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     char8_t s1[] = {1, 2, 3};
     assert(std::char_traits<char8_t>::move(s1, s1+1, 2) == s1);
     assert(s1[0] == char8_t(2));
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/not_eof.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/not_eof.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/not_eof.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/not_eof.pass.cpp
@@ -20,7 +20,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     assert(std::char_traits<char8_t>::not_eof(u8'a') == u8'a');
     assert(std::char_traits<char8_t>::not_eof(u8'A') == u8'A');
     assert(std::char_traits<char8_t>::not_eof(0) == 0);
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_char_type.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_char_type.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_char_type.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_char_type.pass.cpp
@@ -20,7 +20,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     assert(std::char_traits<char8_t>::to_char_type(u8'a') == u8'a');
     assert(std::char_traits<char8_t>::to_char_type(u8'A') == u8'A');
     assert(std::char_traits<char8_t>::to_char_type(0) == 0);
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_int_type.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_int_type.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_int_type.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/to_int_type.pass.cpp
@@ -20,7 +20,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     assert(std::char_traits<char8_t>::to_int_type(u8'a') == u8'a');
     assert(std::char_traits<char8_t>::to_int_type(u8'A') == u8'A');
     assert(std::char_traits<char8_t>::to_int_type(0) == 0);
diff --git a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/types.pass.cpp b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/types.pass.cpp
--- a/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/types.pass.cpp
+++ b/libcxx/test/std/strings/char.traits/char.traits.specializations/char.traits.specializations.char8_t/types.pass.cpp
@@ -26,7 +26,7 @@
 
 int main(int, char**)
 {
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     static_assert((std::is_same<std::char_traits<char8_t>::char_type,  char8_t>::value), "");
     static_assert((std::is_same<std::char_traits<char8_t>::int_type,   unsigned int>::value), "");
     static_assert((std::is_same<std::char_traits<char8_t>::off_type,   std::streamoff>::value), "");
diff --git a/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp b/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp
--- a/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp
+++ b/libcxx/test/std/strings/string.classes/typedefs.compile.pass.cpp
@@ -26,7 +26,7 @@
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
 static_assert((std::is_same<std::wstring, std::basic_string<wchar_t> >::value), "");
 #endif
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
 static_assert((std::is_same<std::u8string, std::basic_string<char8_t> >::value), "");
 #endif
 static_assert((std::is_same<std::u16string, std::basic_string<char16_t> >::value), "");
diff --git a/libcxx/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp b/libcxx/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.hash/enabled_hashes.pass.cpp
@@ -27,7 +27,7 @@
 #ifndef TEST_HAS_NO_WIDE_CHARACTERS
     test_hash_enabled_for_type<std::wstring_view>();
 #endif
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test_hash_enabled_for_type<std::u8string_view>();
 #endif
     test_hash_enabled_for_type<std::u16string_view>();
diff --git a/libcxx/test/std/strings/string.view/string.view.hash/string_view.pass.cpp b/libcxx/test/std/strings/string.view/string.view.hash/string_view.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.hash/string_view.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.hash/string_view.pass.cpp
@@ -61,7 +61,7 @@
 int main(int, char**)
 {
     test<std::string_view>();
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test<std::u8string_view>();
 #endif
     test<std::u16string_view>();
diff --git a/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp b/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.capacity/capacity.pass.cpp
@@ -77,7 +77,7 @@
 
 int main(int, char**) {
     test1<std::string_view> ();
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test1<std::u8string_view> ();
 #endif
     test1<std::u16string_view> ();
@@ -98,7 +98,7 @@
     test2 ( L"", 0 );
 #endif
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test2 ( u8"ABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDEABCDE", 105 );
     test2 ( u8"ABCDE", 5 );
     test2 ( u8"a", 1 );
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/assign.pass.cpp b/libcxx/test/std/strings/string.view/string.view.cons/assign.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.cons/assign.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.cons/assign.pass.cpp
@@ -33,7 +33,7 @@
 int main(int, char**) {
 
     assert( test<std::string_view>    (  "1234"));
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     assert( test<std::u8string_view>  (u8"1234"));
 #endif
 #if TEST_STD_VER >= 11
@@ -46,7 +46,7 @@
 
 #if TEST_STD_VER > 11
     static_assert( test<std::string_view>    ({  "abc", 3}), "");
-#   if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert( test<std::u8string_view>  ({u8"abc", 3}), "");
 #   endif
     static_assert( test<std::u16string_view> ({ u"abc", 3}), "");
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/default.pass.cpp b/libcxx/test/std/strings/string.view/string.view.cons/default.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.cons/default.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.cons/default.pass.cpp
@@ -39,7 +39,7 @@
 int main(int, char**) {
     test<std::string_view> ();
     test<std::u16string_view> ();
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test<std::u8string_view> ();
 #endif
     test<std::u32string_view> ();
diff --git a/libcxx/test/std/strings/string.view/string.view.cons/from_string.pass.cpp b/libcxx/test/std/strings/string.view/string.view.cons/from_string.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.cons/from_string.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.cons/from_string.pass.cpp
@@ -43,7 +43,7 @@
     test ( std::wstring() );
 #endif
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test ( std::u8string{u8"QBCDE"} );
     test ( std::u8string{u8""} );
     test ( std::u8string{} );
diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/begin.pass.cpp
@@ -44,7 +44,7 @@
 int main(int, char**)
 {
     typedef std::string_view    string_view;
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     typedef std::u8string_view  u8string_view;
 #endif
     typedef std::u16string_view u16string_view;
@@ -54,7 +54,7 @@
     test(u16string_view());
     test(u32string_view());
     test(string_view   ( "123"));
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test(u8string_view{u8"123"});
 #endif
 #if TEST_STD_VER >= 11
@@ -71,21 +71,21 @@
 #if TEST_STD_VER > 11
     {
     constexpr string_view       sv { "123", 3 };
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     constexpr u8string_view u8sv  {u8"123", 3 };
 #endif
     constexpr u16string_view u16sv {u"123", 3 };
     constexpr u32string_view u32sv {U"123", 3 };
 
     static_assert (    *sv.begin() ==    sv[0], "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  *u8sv.begin() ==  u8sv[0], "" );
 #endif
     static_assert ( *u16sv.begin() == u16sv[0], "" );
     static_assert ( *u32sv.begin() == u32sv[0], "" );
 
     static_assert (    *sv.cbegin() ==    sv[0], "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  *u8sv.cbegin() ==  u8sv[0], "" );
 #endif
     static_assert ( *u16sv.cbegin() == u16sv[0], "" );
diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/end.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/end.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.iterators/end.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/end.pass.cpp
@@ -53,7 +53,7 @@
 int main(int, char**)
 {
     typedef std::string_view    string_view;
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     typedef std::u8string_view  u8string_view;
 #endif
     typedef std::u16string_view u16string_view;
@@ -63,7 +63,7 @@
     test(u16string_view());
     test(u32string_view());
     test(string_view   ( "123"));
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test(u8string_view{u8"123"});
 #endif
 #if TEST_STD_VER >= 11
@@ -80,21 +80,21 @@
 #if TEST_STD_VER > 11
     {
     constexpr string_view       sv { "123", 3 };
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     constexpr u8string_view u8sv  {u8"123", 3 };
 #endif
     constexpr u16string_view u16sv {u"123", 3 };
     constexpr u32string_view u32sv {U"123", 3 };
 
     static_assert (    sv.begin() !=    sv.end(), "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  u8sv.begin() !=  u8sv.end(), "" );
 #endif
     static_assert ( u16sv.begin() != u16sv.end(), "" );
     static_assert ( u32sv.begin() != u32sv.end(), "" );
 
     static_assert (    sv.begin() !=    sv.cend(), "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  u8sv.begin() !=  u8sv.cend(), "" );
 #endif
     static_assert ( u16sv.begin() != u16sv.cend(), "" );
diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/rbegin.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/rbegin.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.iterators/rbegin.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/rbegin.pass.cpp
@@ -45,7 +45,7 @@
 int main(int, char**)
 {
     typedef std::string_view    string_view;
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     typedef std::u8string_view  u8string_view;
 #endif
     typedef std::u16string_view u16string_view;
@@ -55,7 +55,7 @@
     test(u16string_view());
     test(u32string_view());
     test(string_view   ( "123"));
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test(u8string_view{u8"123"});
 #endif
 #if TEST_STD_VER >= 11
@@ -72,21 +72,21 @@
 #if TEST_STD_VER > 14
     {
     constexpr string_view       sv { "123", 3 };
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     constexpr u8string_view u8sv  {u8"123", 3 };
 #endif
     constexpr u16string_view u16sv {u"123", 3 };
     constexpr u32string_view u32sv {U"123", 3 };
 
     static_assert (    *sv.rbegin() ==    sv[2], "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  *u8sv.rbegin() ==  u8sv[2], "" );
 #endif
     static_assert ( *u16sv.rbegin() == u16sv[2], "" );
     static_assert ( *u32sv.rbegin() == u32sv[2], "" );
 
     static_assert (    *sv.crbegin() ==    sv[2], "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  *u8sv.crbegin() == u8sv[2], "" );
 #endif
     static_assert ( *u16sv.crbegin() == u16sv[2], "" );
diff --git a/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp b/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp
--- a/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string.view.iterators/rend.pass.cpp
@@ -53,7 +53,7 @@
 int main(int, char**)
 {
     typedef std::string_view    string_view;
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     typedef std::u8string_view u8string_view;
 #endif
     typedef std::u16string_view u16string_view;
@@ -63,7 +63,7 @@
     test(u16string_view());
     test(u32string_view());
     test(string_view   ( "123"));
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test(u8string_view{u8"123"});
 #endif
 #if TEST_STD_VER >= 11
@@ -80,21 +80,21 @@
 #if TEST_STD_VER > 14
     {
     constexpr string_view       sv { "123", 3 };
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     constexpr u8string_view u8sv {u8"123", 3 };
 #endif
     constexpr u16string_view u16sv {u"123", 3 };
     constexpr u32string_view u32sv {U"123", 3 };
 
     static_assert (    *--sv.rend() ==    sv[0], "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  *--u8sv.rend() ==  u8sv[0], "" );
 #endif
     static_assert ( *--u16sv.rend() == u16sv[0], "" );
     static_assert ( *--u32sv.rend() == u32sv[0], "" );
 
     static_assert (    *--sv.crend() ==    sv[0], "" );
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#  ifndef TEST_HAS_NO_CHAR8_T
     static_assert (  *--u8sv.crend() ==  u8sv[0], "" );
 #endif
     static_assert ( *--u16sv.crend() == u16sv[0], "" );
diff --git a/libcxx/test/std/strings/string.view/string_view.literals/literal.pass.cpp b/libcxx/test/std/strings/string.view/string_view.literals/literal.pass.cpp
--- a/libcxx/test/std/strings/string.view/string_view.literals/literal.pass.cpp
+++ b/libcxx/test/std/strings/string.view/string_view.literals/literal.pass.cpp
@@ -15,7 +15,7 @@
 
 #include "test_macros.h"
 
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     typedef std::u8string_view u8string_view;
 #else
     typedef std::string_view   u8string_view;
diff --git a/libcxx/test/std/strings/string.view/types.pass.cpp b/libcxx/test/std/strings/string.view/types.pass.cpp
--- a/libcxx/test/std/strings/string.view/types.pass.cpp
+++ b/libcxx/test/std/strings/string.view/types.pass.cpp
@@ -73,7 +73,7 @@
 {
     test<std::char_traits<char> >();
     test<std::char_traits<wchar_t> >();
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test<std::char_traits<char8_t> >();
 #endif
     static_assert((std::is_same<std::basic_string_view<char>::traits_type,
diff --git a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.cat/is_integral.pass.cpp b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.cat/is_integral.pass.cpp
--- a/libcxx/test/std/utilities/meta/meta.unary/meta.unary.cat/is_integral.pass.cpp
+++ b/libcxx/test/std/utilities/meta/meta.unary/meta.unary.cat/is_integral.pass.cpp
@@ -84,7 +84,7 @@
     test_is_integral<signed char>();
     test_is_integral<unsigned char>();
     test_is_integral<wchar_t>();
-#if defined(__cpp_lib_char8_t) && __cpp_lib_char8_t >= 201811L
+#ifndef TEST_HAS_NO_CHAR8_T
     test_is_integral<char8_t>();
 #endif