Another alternative to fix the thread identification problem in coroutines.
We plan to fix this problem by unifying memory effecting attributes. See https://discourse.llvm.org/t/rfc-unify-memory-effect-attributes/65579.
But it may be a long-term project. And it is a pity that the coroutines can't resume in different threads for years. So this one is temporary fix. It may cause unnecessary performance regression for coroutines. But correctness are more important. And this one is planned to be reverted after we are able to unify the memory effecting attributes actually.