[Bug fortran/91473] [10 regression] test case libgomp.fortran/appendix-a/a.28.5.f90 fails starting with r274551

[seurer at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91473

--- Comment #5 from seurer at gcc dot gnu.org ---
For what it's worth several spec 2000 tests also won't compile any more after
this revision.

I guess -std=legacy all around!