[clang] [RFC][C++20][Modules] Fix crash when function and lambda inside loaded from different modules (PR #104512)

[Chuanqi Xu via cfe-commits]

https://github.com/ChuanqiXu9 commented:

I feel the change is somewhat odd to me. Since the description is about the lambda but the change is about VarDecls. I feel there is a mismatch and I feel this may not solve the underlying problem fundamentally. I feel it'll be better to make it more straight forward. e.g., load the context when loading the lambda (or only make it if there is captures.)

https://github.com/llvm/llvm-project/pull/104512