[libc++] Fix feature test macro for __cpp_lib_to_chars
We would have been defining it in <utility> instead of <charconv>. For
the time being, this doesn't change anything since we don't implement
the feature test macro anyways.
Also, as a fly-by, this removes obsolete feature test macro tests. There
was a brief time back in the days when we wrote feature test macro tests
manually. In particular, we had test files for __cpp_lib_to_chars and
__cpp_lib_memory_resource. Since we now have a principled way of generating
these tests with scripts, this commit removes the obsolete (and empty)
tests for these two feature test macros.
Differential Revision: https://reviews.llvm.org/D114243
GitOrigin-RevId: e0f58444e126e80a0d43eb5b88622799910195e6
6 files changed
