[og9] Make OpenACC function-parameter explosion optional

[og9] Make OpenACC function-parameter explosion optional

	* configure.ac (amdgcn*-*-*): Add target-libffi to noconfigdirs for AMD
	GCN.
	* configure: Regenerated.

	gcc/
	* builtin-types.def (BT_FN_VOID_INT_INT_OMPFN_SIZE_PTR_PTR_PTR_VAR):
	Remove.
	* config/i386/i386.c (ix86_goacc_explode_args): New.
	(TARGET_GOACC_EXPLODE_ARGS): Define, using above function.
	* doc/tm.texi: Regenerated.
	* doc/tm.texi.in: Add TARGET_GOACC_EXPLODE_ARGS hook.
	* fortran/types.def (BT_FN_VOID_INT_INT_OMPFN_SIZE_PTR_PTR_PTR_VAR):
	Remove.
	* omp-builtins.def (GOACC_parallel_keyed_v2): Remove.
	* omp-expand.c (expand_omp_target): Use explode_args target hook.
	Use GOMP_LAUNCH_ARGS_EXPLODED launch tag.
	* omp-low.c (build_receiver_ref, build_sender_ref,
	create_omp_child_function, scan_omp_target, lower_omp_target): Use
	explode_args target hook.
	* target.def (explode_args): New target hook.
	* tree-ssa-structalias.c (target.h): Include.
	(find_func_aliases_for_builtin_call): Conditionalise disabling of pass
	for OpenACC parallel regions based on explode_args target hook.  Remove
	'params' from BUILT_IN_GOACC_PARALLEL arguments.
	(find_func_clobbers): Likewise.
	(ipa_pta_execute): Update for removed 'params' argument.

	include/
	* gomp-constants.h (GOMP_LAUNCH_ARGS_EXPLODED): Define.

	libgomp/
	* libgomp.map (GOMP_2.0.GOMP_4_BRANCH): Remove GOACC_parallel_keyed_v2.
	* libgomp_g.h (GOACC_parallel_keyed_v2): Remove prototype.
	* oacc-parallel.c (GOACC_parallel_keyed_internal): Rename to...
	(GOACC_parallel_keyed): ...this.  Handle GOMP_LAUNCH_ARGS_EXPLODED
	launch tag.  Remove previous wrapper functions.
	(GOACC_parallel_keyed_v2): Remove.

(cherry picked from openacc-gcc-9-branch commit
d1a4d60a3bb42efaba6ac417af4116f053d32f93)