Various OpenACC reduction enhancements - FE changes

Various OpenACC reduction enhancements - FE changes

This version differs somewhat from the last version posted upstream
(and addresses some of Jakub's review comments).

2018-12-13  Cesar Philippidis  <cesar@codesourcery.com>
	    Nathan Sidwell  <nathan@acm.org>
	    Julian Brown  <julian@codesourcery.com>

	gcc/c/
	* c-parser.cc (c_parser_omp_variable_list): New c_omp_region_type
	argument.  Use it to specialize handling of OMP_CLAUSE_REDUCTION for
	OpenACC.
	(c_parser_oacc_data_clause): Add region-type argument.
	(c_parser_oacc_data_clause_deviceptr): Likewise.
	(c_parser_omp_clause_reduction): Change is_omp boolean parameter to
	c_omp_region_type.  Update call to c_parser_omp_variable_list.
	(c_parser_oacc_all_clauses): Update calls to
	c_parser_omp_clause_reduction.
	(c_parser_omp_all_clauses): Likewise.
	(c_parser_oacc_cache): Update call to c_parser_omp_var_list_parens.
	* c-typeck.cc (c_finish_omp_clauses): Emit an error on orphan OpenACC
	gang reductions.  Suppress user-defined reduction error for OpenACC.

	gcc/cp/
	* parser.cc (cp_parser_omp_var_list_no_open):  New c_omp_region_type
	argument.  Use it to specialize handling of OMP_CLAUSE_REDUCTION for
	OpenACC.
	(cp_parser_omp_var_list): Add c_omp_region_type argument. Update call
	to cp_parser_omp_var_list_parens.
	(cp_parser_oacc_data_clause): Update call to cp_parser_omp_var_list.
	(cp_parser_omp_clause_reduction): Change is_omp boolean parameter to
	c_omp_region_type.  Update call to cp_parser_omp_var_list_no_open.
	(cp_parser_oacc_all_clauses): Update call to
	cp_parser_omp_clause_reduction.
	(cp_parser_omp_all_clauses): Likewise.
	* semantics.cc (finish_omp_reduction_clause): Add c_omp_region_type
	argument.  Suppress user-defined reduction error for OpenACC.
	(finish_omp_clauses): Emit an error on orphan OpenACC gang reductions.

	gcc/fortran/
	* openmp.cc (oacc_is_parallel): New.
	(resolve_oacc_loop_blocks): Emit an error on orphan OpenACC
	gang reductions.
	* trans-openmp.cc (gfc_omp_clause_copy_ctor): Permit reductions.

2022-02-03  Kwok Cheung Yeung  <kcy@codesourcery.com>

	gcc/c/
	* c-parser.cc (c_parser_omp_clause_map): Update call to
	c_parser_omp_variable_list.
	(c_parser_omp_clause_to): Update call to c_parser_omp_var_list_parens.
	(c_parser_omp_clause_from): Likewise.

	gcc/cp/
	* parser.cc (cp_parser_omp_clause_map): Update call to
	cp_parser_omp_var_list_no_open.
	(cp_parser_omp_all_clauses): Update calls to cp_parser_omp_var_list.