[llvm] [offload][nfc] Move AsyncInfoTy's definitions to libompaccsupport (PR #220991)

[Ivan R. Ivanov via llvm-commits]

ivanradanov wrote:

Thank you for the comments.

This concerns the reuse of infra between libomptarget and libacctarget, and is cleaning up the entaglement between libompaccsupport and libomptarget, so that libompaccsupport can be used by libaccsupport independently.

The interface between libomptarget and liboffload is a separate concern and as @adurang pointed out we want to eventually move away from using the internal liboffload structures and using only public APIs, so I think this patch is unrelated to that goal.

https://github.com/llvm/llvm-project/pull/220991