[libc++][test] Fix unused variable warning in string_view tests

[jloser]

Summary

In 6423a9f0ec8ba70049ea76e7bcfc9a9d1a54e826, I accidentally thought this was
getting tested, but these variables are unused. Just remove the lines instead of
leaving them commented out.

[Mordante]

Thanks! LGTM after addressing the review comments.

libcxx/test/std/strings/string.view/string.view.template/ends_with.ptr.pass.cpp

68

Remove these too please.

libcxx/test/std/strings/string.view/string.view.template/starts_with.ptr.pass.cpp

70

Remove these too please.

libcxx/test/std/strings/string.view/string.view.template/ends_with.ptr.pass.cpp

 int main(int, char**)
 {
     {
     typedef std::string_view SV;
     const char *s = "abcde";
     SV  sv0 {};
     SV  sv1 { s + 4, 1 };
     SV  sv2 { s + 3, 2 };
-    SV  sv3 { s + 2, 3 };
-    SV  sv4 { s + 1, 4 };
-    SV  sv5 { s    , 5 };
     SV  svNot {"def", 3 };
 
     LIBCPP_ASSERT_NOEXCEPT(sv0.ends_with(""));
 
     assert ( sv0.ends_with(""));
     assert (!sv0.ends_with("e"));
 
     assert ( sv1.ends_with(""));

 
 #if TEST_STD_VER > 11
     {
     typedef std::basic_string_view<char, constexpr_char_traits<char>> SV;
     constexpr const char *s = "abcde";
     constexpr SV  sv0 {};
     constexpr SV  sv1 { s + 4, 1 };
     constexpr SV  sv2 { s + 3, 2 };
 //     constexpr SV  sv3 { s + 2, 3 };
 //     constexpr SV  sv4 { s + 1, 4 };
 //     constexpr SV  sv5 { s,     5 };
     constexpr SV  svNot {"def", 3 };
 
     static_assert ( sv0.ends_with(""), "" );
     static_assert (!sv0.ends_with("e"), "" );
 
     static_assert ( sv1.ends_with(""), "" );

libcxx/test/std/strings/string.view/string.view.template/starts_with.ptr.pass.cpp

 int main(int, char**)
 {
     {
     typedef std::string_view SV;
     const char *s = "abcde";
     SV  sv0 {};
     SV  sv1 { s, 1 };
     SV  sv2 { s, 2 };
-    SV  sv3 { s, 3 };
-    SV  sv4 { s, 4 };
-    SV  sv5 { s, 5 };
     SV  svNot {"def", 3 };
 
     LIBCPP_ASSERT_NOEXCEPT(sv0.starts_with(""));
 
     assert ( sv0.starts_with(""));
     assert (!sv0.starts_with("a"));
 
     assert ( sv1.starts_with(""));
#if TEST_STD_VER > 11
     {
     typedef std::basic_string_view<char, constexpr_char_traits<char>> SV;
     constexpr const char *s = "abcde";
     constexpr SV  sv0 {};
     constexpr SV  sv1 { s, 1 };
     constexpr SV  sv2 { s, 2 };
 //     constexpr SV  sv3 { s, 3 };
 //     constexpr SV  sv4 { s, 4 };
 //     constexpr SV  sv5 { s, 5 };
     constexpr SV  svNot {"def", 3 };
 
     static_assert ( sv0.starts_with(""), "" );
     static_assert (!sv0.starts_with("a"), "" );
 
     static_assert ( sv1.starts_with(""), "" );
     static_assert ( sv1.starts_with("a"), "" );
     static_assert (!sv1.starts_with("ab"), "" );