[llvm] [llvm/llvm-project][Coroutines] Move the SuspendCrossingInfo analysis helper into its own header/source (PR #106306)

[Chuanqi Xu via llvm-commits]

https://github.com/ChuanqiXu9 approved this pull request.

LGTM. 

nit: please remove the prefix '[llvm/llvm-project]' in the title when committing.

https://github.com/llvm/llvm-project/pull/106306