[clang] [Clang] Don't suppress vtable emission for classes with -fmodules-debuginfo (PR #204662)

[Chuanqi Xu via cfe-commits]

https://github.com/ChuanqiXu9 commented:

Looks not bad. Just two questions:

1. With -fmodules-debuginfo, `shouldEmitInExternalSource` will return true. So i think it will emit the debug info file but not the object file, right? I am wondering if it is better to make `shouldEmitInExternalSource`  to return true for such cases?
2. Does -fmodules-debuginfo work for C++20 modules? Or should it ?

https://github.com/llvm/llvm-project/pull/204662