[clang] [CIR] Make the post-CIRGen emission path independent of ASTContext (PR #229441)

[Erich Keane via cfe-commits]

https://github.com/erichkeane commented:

oh wait, did some goofy stuff happen with a merge?  I'm only seeing the CIRGenAction.cpp changes, but I see comments elsewhere.

https://github.com/llvm/llvm-project/pull/229441