[llvm] [coroutines][CoroSplit] Store allocas on the frame if there is no explicit lifetime.end (PR #88806)

[Alan Zhao via llvm-commits]

alanzhao1 wrote:

I started a discourse thread at https://discourse.llvm.org/t/coro-using-lifetime-markers-to-allocate-values-on-the-stack-vs-the-frame/78451

https://github.com/llvm/llvm-project/pull/88806