[clang] [clang][Modules] Keep current-TU global-module-fragment internal-linkage functions viable in overload resolution (PR #210825)

[Chuanqi Xu via cfe-commits]

https://github.com/ChuanqiXu9 commented:

BTW, if this is AI assisted, please note that. Ignore this if this is not AI assisted.

https://github.com/llvm/llvm-project/pull/210825