OpenACC: Further attach/detach clause fixes for Fortran [PR109622]

This patch moves several tests introduced by the following patch:

  https://gcc.gnu.org/pipermail/gcc-patches/2023-April/616939.html
  commit r14-325-gcacf65d74463600815773255e8b82b4043432bd7

into the proper location for OpenACC testing (thanks to Thomas for
spotting my mistake!), and also fixes a few additional problems --
missing diagnostics for non-pointer attaches, and a case where a pointer
was incorrectly dereferenced. Tests are also adjusted for vector-length
warnings on nvidia accelerators.

2023-04-29  Julian Brown  <julian@codesourcery.com>

	PR fortran/109622

gcc/fortran/
	* openmp.cc (resolve_omp_clauses): Add diagnostic for
	non-pointer/non-allocatable attach/detach.
	* trans-openmp.cc (gfc_trans_omp_clauses): Remove dereference for
	pointer-to-scalar derived type component attach/detach.  Fix
	attach/detach handling for descriptors.

gcc/testsuite/
	* gfortran.dg/goacc/pr109622-5.f90: New test.
	* gfortran.dg/goacc/pr109622-6.f90: New test.

libgomp/
	* testsuite/libgomp.fortran/pr109622.f90: Move test...
	* testsuite/libgomp.oacc-fortran/pr109622.f90: ...to here. Ignore
	vector length warning.
	* testsuite/libgomp.fortran/pr109622-2.f90: Move test...
	* testsuite/libgomp.oacc-fortran/pr109622-2.f90: ...to here.  Add
	missing copyin/copyout variable. Ignore vector length warnings.
	* testsuite/libgomp.fortran/pr109622-3.f90: Move test...
	* testsuite/libgomp.oacc-fortran/pr109622-3.f90: ...to here.  Ignore
	vector length warnings.
	* testsuite/libgomp.oacc-fortran/pr109622-4.f90: New test.

(cherry picked from commit 0a26a42b)