Add support for allocate clause (OpenMP 5.0).

Add support for allocate clause (OpenMP 5.0).

This patch adds support for OpenMP 5.0 allocate clause for fortran. It does not
yet support the allocator-modifier as specified in OpenMP 5.1. The allocate
clause is already supported in C/C++.

This commit contains 4 following upstream commits.

69561fc781a Add support for allocate clause (OpenMP 5.0).
deb9f18f677 Change kind of integer literal to fix a testcase.
6d498135016 libgomp.fortran/allocate-1.f90: Minor cleanup
f62156eab7b libgomp.fortran/allocate-1.f90: Fix minor cleanup

gcc/fortran/ChangeLog:

	* dump-parse-tree.c (show_omp_clauses): Handle OMP_LIST_ALLOCATE.
	* gfortran.h (OMP_LIST_ALLOCATE): New enum value.
	* openmp.c (enum omp_mask1): Add OMP_CLAUSE_ALLOCATE.
	(gfc_match_omp_clauses): Handle OMP_CLAUSE_ALLOCATE
	(OMP_PARALLEL_CLAUSES, OMP_DO_CLAUSES, OMP_SECTIONS_CLAUSES)
	(OMP_TASK_CLAUSES, OMP_TASKLOOP_CLAUSES, OMP_TARGET_CLAUSES)
	(OMP_TEAMS_CLAUSES, OMP_DISTRIBUTE_CLAUSES)
	(OMP_SINGLE_CLAUSES): Add OMP_CLAUSE_ALLOCATE.
	(OMP_TASKGROUP_CLAUSES): New.
	(gfc_match_omp_taskgroup): Use OMP_TASKGROUP_CLAUSES instead of
	OMP_CLAUSE_TASK_REDUCTION.
	(resolve_omp_clauses): Handle OMP_LIST_ALLOCATE.
	(resolve_omp_do): Avoid warning when loop iteration variable is
	in allocate clause.
	* trans-openmp.c (gfc_trans_omp_clauses): Handle translation of
	allocate clause.
	(gfc_split_omp_clauses): Update for OMP_LIST_ALLOCATE.

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/allocate-1.f90: New test.
	* gfortran.dg/gomp/allocate-2.f90: New test.
	* gfortran.dg/gomp/allocate-3.f90: New test.
	* gfortran.dg/gomp/collapse1.f90: Update error message.
	* gfortran.dg/gomp/openmp-simd-4.f90: Likewise.
	* gfortran.dg/gomp/clauses-1.f90: Uncomment allocate clause.

libgomp/ChangeLog:

	* testsuite/libgomp.fortran/allocate-1.c: New test.
	* testsuite/libgomp.fortran/allocate-1.f90: New test.
	* libgomp.texi: Remove string that says that allocate clause
	support is for C/C++ only.

(cherry picked from commit 69561fc781aca3dea3aa4d5d562ef5a502965924)

Change kind of integer literal to fix a testcase.

As Thomas reported in
https://gcc.gnu.org/pipermail/gcc-patches/2022-January/588448.html
a test added in my recent allocate clause patch fails on m32. It was due
to default kind for integer matching c_intptr_t for m32. I have now
changed it to 0_1 so that always integer with kind=1 is used.

gcc/testsuite/ChangeLog:

	* gfortran.dg/gomp/allocate-2.f90: Change 0 to 0_1.

(cherry picked from commit deb9f18f67788c36f4652bca101d93faf07ecf39)

libgomp.fortran/allocate-1.f90: Minor cleanup

libgomp/ChangeLog:
	* testsuite/libgomp.fortran/allocate-1.c (is_64bit_aligned): Renamed
	from is_64bit_aligned_.
	* testsuite/libgomp.fortran/allocate-1.f90: Fix interface decl
	and use it, more implicit none, remove unused argument.

(cherry picked from commit 6d4981350168f1eb3f72149bd7e05b9ba6bec1fd)

libgomp.fortran/allocate-1.f90: Fix minor cleanup

libgomp/ChangeLog:
	* testsuite/libgomp.fortran/allocate-1.f90: Remove spurious
	STOP of previous commit.

(cherry picked from commit f62156eab7b757d1ee03a11d5c96c72bd3de079c)