[Bug libgomp/88495] New: An OpenACC async queue is always synchronized with itself

["tschwinge at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88495

            Bug ID: 88495
           Summary: An OpenACC async queue is always synchronized with
                    itself
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: openacc, patch
          Severity: normal
          Priority: P3
         Component: libgomp
          Assignee: tschwinge at gcc dot gnu.org
          Reporter: tschwinge at gcc dot gnu.org
                CC: cltang at gcc dot gnu.org, jakub at gcc dot gnu.org
  Target Milestone: ---

An OpenACC async queue is always synchronized with itself, so invocations like
"#pragma acc wait(0) async(0)", or "acc_wait_async(0, 0)" don't make a lot of
sense, but are still valid.

This will need to be fixed on all release branches.

I have a patch.