[clang] [Win32][Coroutine] Fix inalloca arguments lifetime in coroutines (PR #212331)

[via cfe-commits]

naeioi wrote:

(Driven by while I was exploring coroutine to Chromium and ran into this issue). 

@efriedma-quic , Eli, could you take some time to review Etienne's latest change? This will unblock Chromium from using C++ 20 coroutine. Thank you.

https://github.com/llvm/llvm-project/pull/212331