[Bug fortran/121043] New: [15/16 Regression] Tests of OpenCoarray fail to pass, works on 14.3.1 20250701

[jvdelisle at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121043

            Bug ID: 121043
           Summary: [15/16 Regression] Tests of OpenCoarray fail to pass,
                    works on 14.3.1 20250701
           Product: gcc
           Version: 16.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: jvdelisle at gcc dot gnu.org
  Target Milestone: ---

Starting with a clean build directory, building OpenCoarrays works but the
tests fail. In particular, Test  #4: register_alloc_vector hangs when
performing make test. Obviously we broke something. I have not been able to
isolate this.