I stumbled over this omission when looking at Sandra's patch. It turned out that this is
a new OpenMP 5.2 feature - probably added to simplify/unify the syntax. I guess the reason
that release/acquire wasn't added before is that it cannot be universally be used - read/write
do only accept one of them.

However, as a compilation unit might only/mostly use read (and update) or write (and update),
that can be fine - especially as overriding the default clause is still possible.

It is not quite clear to me why, but the current patch also fixes a bug regarding the
diagnostic message for gfortran.dg/gomp/requires-5.f90. (I think I could find out, but
as it changed to the better...)

Comments, suggestions?

Tobias
-----------------
Siemens Electronic Design Automation GmbH; Anschrift: Arnulfstraße 201, 80634 München; Gesellschaft mit beschränkter Haftung; Geschäftsführer: Thomas Heurung, Frank Thürauf; Sitz der Gesellschaft: München; Registergericht München, HRB 106955