[clang] [Clang] Fix dependent local class instantiation bugs (PR #134038)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

This once again looks like an attempt at hacking around our lack of delayed lambda body instantiation... And this one has some pretty sizable negatives as far as I can see.  I'm not sure I really like this direction.

https://github.com/llvm/llvm-project/pull/134038