[libc++] Add missing annotations for TEST_HAS_NO_WIDE_CHARACTERS

[ldionne]

Summary

Those tests would pass when run on a C Standard Library that actually
provides wide characters, but fail when run on top of one that doesn't.
It's really difficult to test this 100% perfectly in the CI without
introducing an actual platform that doesn't provide these declarations.

libcxx/test/std/depr/depr.c.headers/inttypes_h.pass.cpp

int main(int, char**)
     }
 
     intmax_t i = 0;
     ((void)i); // Prevent unused warning
     static_assert((std::is_same<decltype(imaxabs(i)), intmax_t>::value), "");
     static_assert((std::is_same<decltype(imaxdiv(i, i)), imaxdiv_t>::value), "");
     static_assert((std::is_same<decltype(strtoimax("", (char**)0, 0)), intmax_t>::value), "");
     static_assert((std::is_same<decltype(strtoumax("", (char**)0, 0)), uintmax_t>::value), "");
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
     static_assert((std::is_same<decltype(wcstoimax(L"", (wchar_t**)0, 0)), intmax_t>::value), "");
     static_assert((std::is_same<decltype(wcstoumax(L"", (wchar_t**)0, 0)), uintmax_t>::value), "");
+#endif
 
   return 0;
 }

libcxx/test/std/depr/depr.c.headers/stdlib_h.pass.cpp

int main(int, char**)
     static_assert((std::is_same<decltype(bsearch(pv,pv,0,0,comp)), void*>::value), "");
     static_assert((std::is_same<decltype(qsort(pv,0,0,comp)), void>::value), "");
     static_assert((std::is_same<decltype(abs(0)), int>::value), "");
     static_assert((std::is_same<decltype(labs((long)0)), long>::value), "");
     static_assert((std::is_same<decltype(llabs((long long)0)), long long>::value), "");
     static_assert((std::is_same<decltype(div(0,0)), div_t>::value), "");
     static_assert((std::is_same<decltype(ldiv(0L,0L)), ldiv_t>::value), "");
     static_assert((std::is_same<decltype(lldiv(0LL,0LL)), lldiv_t>::value), "");
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
     wchar_t* pw = 0;
     const wchar_t* pwc = 0;
     char* pc = 0;
     static_assert((std::is_same<decltype(mblen("",0)), int>::value), "");
     static_assert((std::is_same<decltype(mbtowc(pw,"",0)), int>::value), "");
     static_assert((std::is_same<decltype(wctomb(pc,L' ')), int>::value), "");
     static_assert((std::is_same<decltype(mbstowcs(pw,"",0)), size_t>::value), "");
     static_assert((std::is_same<decltype(wcstombs(pc,pwc,0)), size_t>::value), "");
+#endif
 
     test_abs();
 
     return 0;
 }

libcxx/test/std/language.support/support.runtime/cstdlib.pass.cpp

int main(int, char**)
     static_assert((std::is_same<decltype(std::abs((long long)0)), long long>::value), "");
     static_assert((std::is_same<decltype(std::labs((long)0)), long>::value), "");
     static_assert((std::is_same<decltype(std::llabs((long long)0)), long long>::value), "");
     static_assert((std::is_same<decltype(std::div(0,0)), std::div_t>::value), "");
     static_assert((std::is_same<decltype(std::div(0L,0L)), std::ldiv_t>::value), "");
     static_assert((std::is_same<decltype(std::div(0LL,0LL)), std::lldiv_t>::value), "");
     static_assert((std::is_same<decltype(std::ldiv(0L,0L)), std::ldiv_t>::value), "");
     static_assert((std::is_same<decltype(std::lldiv(0LL,0LL)), std::lldiv_t>::value), "");
+#ifndef TEST_HAS_NO_WIDE_CHARACTERS
     wchar_t* pw = 0;
     const wchar_t* pwc = 0;
     char* pc = 0;
     static_assert((std::is_same<decltype(std::mblen("",0)), int>::value), "");
     static_assert((std::is_same<decltype(std::mbtowc(pw,"",0)), int>::value), "");
     static_assert((std::is_same<decltype(std::wctomb(pc,L' ')), int>::value), "");
     static_assert((std::is_same<decltype(std::mbstowcs(pw,"",0)), std::size_t>::value), "");
     static_assert((std::is_same<decltype(std::wcstombs(pc,pwc,0)), std::size_t>::value), "");
+#endif
 
     test_abs();
 
     return 0;
 }