[Bug c++/77299] [9/10/11/12 Regression] No warning for unused "INT64_MAX" and similar constants due macro tracking from system headers

[redi at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77299

--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> ---
For the "NULL hiding pedwarn about invalid C++11 code in C++98" case from PR
103347

#include <cstddef>
struct test {
    void *x = NULL; //invalid in C++03 mode
};
int main() {}

The missing warning regression started with r186977, when
-ftrack-macro-expansion=2 became the default.