Compile fix for Clang + libc++ (#91212)
Summary:
LLVM 15 has a compile issue with the deprecated __has_trivial_copy. Update the GCC ifdef logic to exclude Clang + libc++.
```
caffe2/c10/util/Optional.h:536:13: error: builtin __has_trivial_copy is deprecated; use __is_trivially_copyable instead [-Werror,-Wdeprecated-builtins]
C10_IS_TRIVIALLY_COPYABLE(T) &&
^
caffe2/c10/macros/Macros.h:438:38: note: expanded from macro 'C10_IS_TRIVIALLY_COPYABLE'
#define C10_IS_TRIVIALLY_COPYABLE(T) __has_trivial_copy(T)
```
Test Plan: CI
Reviewed By: kit1980
Differential Revision: D42180203
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91212
Approved by: https://github.com/kit1980, https://github.com/soumith
