[clang][modules] stdarg.h and stddef.h shouldn't directly declare anything (#90676)
stdarg.h and especially stddef.h are textual and so everything they
declare gets precompiled into all of their clients' pcm files. They
shouldn't directly declare anything though, their purpose is to select
what submodules get imported, and not to add duplicate declarations to
all of their clients. Make it so that they always ignore their header
guards, even without modules, and declare them in separate header files
so that they only go into the stdarg/stddef pcms. Still declare them in
case clients rely on them.
GitOrigin-RevId: 29d447a6e446e7fd78bd28af28bbf7dd377ade10
2 files changed
