[libcxx] [test] Move a missed test to ctime.timespec.compile.pass.cpp

[mstorsjo]

Summary

This was missed in ec574f5da463d303a3771597c233e52d2429db67. TIME_UTC
is a define that belongs together with timespec_get. The testcase
it's moved to is only run for >= C++17, so the surrounding ifdef guard
can be dropped.

[ldionne]

Thanks for the catch!

[mstorsjo]

Retrigger CI

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

 #ifndef NULL
 #error NULL not defined
 #endif
 
 #ifndef CLOCKS_PER_SEC
 #error CLOCKS_PER_SEC not defined
 #endif
 
-#if TEST_STD_VER > 14
-#ifndef TIME_UTC
-#error TIME_UTC not defined
-#endif
-#endif
-
 int main(int, char**)
 {
     std::clock_t c = 0;
     std::size_t s = 0;
     std::time_t t = 0;
     std::tm tm = {};
     // std::timespec and std::timespec_get tested in ctime.timespec.compile.pass.cpp
     ((void)c); // Prevent unused warning

libcxx/test/std/language.support/support.runtime/ctime.timespec.compile.pass.cpp

 
 // ::timespec_get is provided by the C library, but it's marked as
 // unavailable until macOS 10.15
 // XFAIL: use_system_cxx_lib && target={{.+}}-apple-macosx10.{{9|10|11|12|13|14}}
 
 #include <ctime>
 #include <type_traits>
 
+#ifndef TIME_UTC
+#error TIME_UTC not defined
+#endif
+
 std::timespec tmspec = {};
 static_assert(std::is_same<decltype(std::timespec_get(&tmspec, 0)), int>::value, "");