[llvm] [X86][WinEH] Restore parent RSP before Win64 catchret continuation (PR #191616)

[via llvm-commits]

taigacon wrote:

I’ve rebased the branch onto the current main, resolved the conflicts, and force-pushed the updated branch, so I’ll wait for the new CI results first.

I’ll add explicit coverage for allocas with alignment greater than 16 next.

https://github.com/llvm/llvm-project/pull/191616