clang-tidy gives incorrect result for __has_builtin

[russellmcc]

clang-tidy sometimes gives the wrong result for __has_builtin.

For example:

#if !__has_builtin(__builtin_os_log_format)
#error "Needs built-in"
#endif

int main() {}

gives an error (https://godbolt.org/z/fWdz4zx6h), even though the built-in is actually there (https://godbolt.org/z/oE567Yeve)

[llvmbot]

@llvm/issue-subscribers-clang-tidy

[russellmcc]

Apparently this only happens in -std=c++20

[PiotrZSL]

Duplicate of #50087.
https://discourse.llvm.org/t/rfc-expand-modular-headers-ppcallbacks-problem-in-c-20/71628