GCC recommends not using them for a long time and its documentation says:
> These #pragmas have been superceded as of GCC 2.7.2 by COMDAT support
> and the “key method” heuristic mentioned in Vague Linkage.
> Using them can actually cause your program to grow due to
> unnecessary out-of-line copies of inline functions.

Also nobody seems to set USE_GCC_PRAGMAS and sometimes they were
guarded by just __GNUC__ which upsets Clang.