[clang] [Clang] Fix FE crash during CGCoroutine GRO Alloca Emission (PR #148962)

[Adrian Vogelsgesang via cfe-commits]

vogelsgesang wrote:

> Would like to. Please advise next steps.

efriedma already took care of creating the PR for the backport via the `/cherry-pick c36156d` command. It's now up to the original approver (@bcardosolopes) to also approve that backport PR. The goal of that second review is primarily to judge if this change is carries any risk to destabilize the upcoming release. (Usually, I think bug fixes, in particular early during the release cycle, carry little risk. That being said, I didn't look at the actual code changes here)

https://github.com/llvm/llvm-project/pull/148962