[clang] [C++20][Modules] Fix crash when function and lambda inside loaded from different modules (PR #109167)

[Dmitry Polukhin via cfe-commits]

dmpolukhin wrote:

@ChuanqiXu9 thank you for the detailed steps, I uploaded new version. Does it look like something you had in mind?

https://github.com/llvm/llvm-project/pull/109167