[clang] [Clang] Track temporary cleanups in rebuilt default member initializers (PR #196597)

[Eli Friedman via cfe-commits]

https://github.com/efriedma-quic commented:

I wrote up some thoughts on issues in this area in https://github.com/llvm/llvm-project/issues/85601#issuecomment-3100319152 .

I think we need to more fundamentally rethink how we do this. I think we need to more explicitly fork the codepaths so the various scopes and context is correct.  Trying to explicitly fixup various subexpressions will lead to a bunch of subtle bugs.  In particular, I think we shouldn't EnterExpressionEvaluationContext in the aggregate case.

https://github.com/llvm/llvm-project/pull/196597