openmp, fortran: Check that the type of an event handle in a detach clause is suitabl...

openmp, fortran: Check that the type of an event handle in a detach clause is suitable [PR104131]

This rejects variables that are array types, array elements or derived type
members when used as the event handle inside a detach clause (in accordance
with the OpenMP specification).  This would previously lead to an ICE.

2022-03-03  Kwok Cheung Yeung  <kcy@codesourcery.com>

gcc/fortran/

	PR fortran/104131
	* openmp.cc (gfc_match_omp_detach): Move check for type of event
	handle to...
	(resolve_omp_clauses) ...here.  Also check that the event handle is
	not an array, or an array access or structure element access.

gcc/testsuite/

	PR fortran/104131
	* gfortran.dg/gomp/pr104131.f90: New.
	* gfortran.dg/gomp/task-detach-1.f90: Update expected error message.