PR c/65467
	* gimplify.c (gimplify_adjust_omp_clauses_1): Diagnose implicit
	map and firstprivate clauses on target construct for _Atomic
	qualified decls.
	(gimplify_adjust_omp_clauses): Diagnose explicit firstprivate clauses
	on target construct for _Atomic qualified decls.
	* omp-low.c (use_pointer_for_field): Return true for _Atomic qualified
	decls.
	* omp-simd-clone.c (simd_clone_clauses_extract): Warn and give up for
	_Atomic qualified arguments not mentioned in uniform clause.
c/
	* c-parser.c (c_parser_declspecs): Don't sorry about _Atomic if
	flag_openmp.
	(c_parser_omp_variable_list): Use convert_lvalue_to_rvalue
	instead of mark_exp_read on low_bound/length expression.
	(c_parser_omp_clause_num_gangs, c_parser_omp_clause_num_threads,
	c_parser_omp_clause_num_tasks, c_parser_omp_clause_grainsize,
	c_parser_omp_clause_priority, c_parser_omp_clause_hint,
	c_parser_omp_clause_num_workers, c_parser_oacc_shape_clause,
	c_parser_oacc_clause_tile, c_parser_omp_clause_schedule,
	c_parser_omp_clause_vector_length, c_parser_omp_clause_num_teams,
	c_parser_omp_clause_thread_limit, c_parser_omp_clause_aligned,
	c_parser_omp_clause_linear, c_parser_omp_clause_safelen,
	c_parser_omp_clause_simdlen, c_parser_omp_clause_device,
	c_parser_omp_clause_dist_schedule): Use convert_lvalue_to_rvalue
	instead of mark_expr_read.
	(c_parser_omp_declare_reduction): Reject _Atomic qualified types.
	* c-objc-common.h (LANG_HOOKS_OMP_CLAUSE_COPY_CTOR,
	LANG_HOOKS_OMP_CLAUSE_ASSIGN_OP): Redefine.
	* c-tree.h (c_omp_clause_copy_ctor): New prototype.
	* c-typeck.c (handle_omp_array_sections_1): Diagnose _Atomic qualified
	array section bases outside of depend clause, for depend clause
	use convert_lvalue_to_rvalue on the base.
	(c_finish_omp_clauses): Reject _Atomic qualified vars in reduction,
	linear, aligned, map, to and from clauses.
	(c_omp_clause_copy_ctor): New function.
c-family/
	* c-omp.c (c_finish_omp_atomic): Reject _Atomic qualified expressions.
	(c_finish_omp_for): Reject _Atomic qualified iterators.
testsuite/
	* gcc.dg/gomp/_Atomic-1.c: New test.
	* gcc.dg/gomp/_Atomic-2.c: New test.
	* gcc.dg/gomp/_Atomic-3.c: New test.
	* gcc.dg/gomp/_Atomic-4.c: New test.
	* gcc.dg/gomp/_Atomic-5.c: New test.

From-SVN: r239964