Add support for OpenACC routine nohost clause

Add support for OpenACC routine nohost clause

2018-10-02  Thomas Schwinge  <thomas@codesourcery.com>
	    Cesar Philippidis  <cesar@codesourcery.com>

	gcc/
	* tree-core.h (omp_clause_code): Add OMP_CLAUSE_NOHOST.
	* tree.c (omp_clause_num_ops, omp_clause_code_name, walk_tree_1):
	Update for these.
	* tree-pretty-print.c (dump_omp_clause): Handle	OMP_CLAUSE_NOHOST.
	* gimplify.c (gimplify_scan_omp_clauses)
	(gimplify_adjust_omp_clauses): Handle OMP_CLAUSE_NOHOST.
	* tree-nested.c (convert_nonlocal_omp_clauses)
	(convert_local_omp_clauses): Likewise.
	* omp-low.c (scan_sharing_clauses): Likewise.
	* omp-offload.c (maybe_discard_oacc_function): New function.
	(execute_oacc_device_lower) [!ACCEL_COMPILER]: Handle OpenACC
	nohost clauses.

	gcc/c-family/
	* c-attribs.c (c_common_attribute_table): Set min_len to -1 for
	"omp declare target".
	* c-pragma.h (pragma_omp_clause): Add PRAGMA_OACC_CLAUSE_NOHST.

	gcc/c/
	* c-parser.c (c_parser_omp_clause_name): Handle "nohost".
	(c_parser_oacc_all_clauses): Handle PRAGMA_OACC_CLAUSE_NOHOST.
	(c_parser_oacc_routine, c_finish_oacc_routine): Update.
	* c-typeck.c (c_finish_omp_clauses): Handle OMP_CLAUSE_NOHOST.

	gcc/cp/
	* parser.c (cp_parser_omp_clause_name): Handle "nohost".
	(cp_parser_oacc_all_clauses): Handle PRAGMA_OACC_CLAUSE_NOHOST,
	(cp_parser_oacc_routine, cp_finalize_oacc_routine): Update.
	* pt.c (tsubst_omp_clauses): Handle OMP_CLAUSE_NOHOST.
	* semantics.c (finish_omp_clauses): Handle OMP_CLAUSE_NOHOST.

	gcc/fortran/
	* gfortran.h (gfc_omp_clauses): Add nohost members.
	* openmp.c (omp_mask2): Add OMP_CLAUSE_NOHOST.
	(gfc_match_omp_clauses): Handle OMP_CLAUSE_NOHOST.
	(gfc_match_oacc_routine): Set oacc_function_nohost when appropriate.
	* gfortran.h (symbol_attribute): Add oacc_function_nohost member.
	* trans-openmp.c (gfc_add_omp_offload_attributes): Use it to decide
	whether to generate an OMP_CLAUSE_NOHOST clause.
	(gfc_trans_omp_clauses_1): Unreachable code to generate an
	OMP_CLAUSE_NOHOST clause.

	gcc/testsuite/
	* c-c++-common/goacc/classify-routine.c: Adjust test.
	* c-c++-common/goacc/routine-1.c: Likewise.
	* c-c++-common/goacc/routine-2.c: Likewise.
	* c-c++-common/goacc/routine-nohost-1.c: New test.
	* g++.dg/goacc/routine-2.C: Adjust test.
	* gfortran.dg/goacc/pr72741.f90: New test.

	libgomp/
	* testsuite/libgomp.oacc-c-c++-common/routine-3.c: New test.
	* testsuite/libgomp.oacc-c-c++-common/routine-nohost-1.c: New test.
	* testsuite/libgomp.oacc-c-c++-common/routine-bind-nohost-1.c:
	Update test.
	* testsuite/libgomp.oacc-fortran/routine-6.f90: Likewise.

(cherry picked from openacc-gcc-9-branch commit
a6ec4f19ff50a91a7b0a8c3663e49c071b506016)