[coro async] Don't promote allocas to the frame or rewrite swifterror if...

[coro async] Don't promote allocas to the frame or rewrite  swifterror if there are no suspend points

Also don't call function to update the call graph if there are no
clones. The function will fail.

rdar://74277860

Differential Revision: https://reviews.llvm.org/D96620