Use plain -fopenacc to enable OpenACC kernels processing

Use plain -fopenacc to enable OpenACC kernels processing

	gcc/
	* tree-parloops.c (create_parallel_loop, gen_parallel_loop)
	(parallelize_loops): In OpenACC kernels mode, set n_threads to
	zero.
	(pass_parallelize_loops::gate): In OpenACC kernels mode, gate on
	flag_openacc.
	* tree-ssa-loop.c (gate_oacc_kernels): Likewise.
	gcc/testsuite/
	* c-c++-common/goacc/kernels-counter-vars-function-scope.c: Adjust
	to -ftree-parallelize-loops/-fopenacc changes.
	* c-c++-common/goacc/kernels-double-reduction-n.c: Likewise.
	* c-c++-common/goacc/kernels-double-reduction.c: Likewise.
	* c-c++-common/goacc/kernels-loop-2.c: Likewise.
	* c-c++-common/goacc/kernels-loop-3.c: Likewise.
	* c-c++-common/goacc/kernels-loop-g.c: Likewise.
	* c-c++-common/goacc/kernels-loop-mod-not-zero.c: Likewise.
	* c-c++-common/goacc/kernels-loop-n.c: Likewise.
	* c-c++-common/goacc/kernels-loop-nest.c: Likewise.
	* c-c++-common/goacc/kernels-loop.c: Likewise.
	* c-c++-common/goacc/kernels-one-counter-var.c: Likewise.
	* c-c++-common/goacc/kernels-reduction.c: Likewise.
	* gfortran.dg/goacc/kernels-loop-inner.f95: Likewise.
	* gfortran.dg/goacc/kernels-loops-adjacent.f95: Likewise.
	libgomp/
	* oacc-parallel.c (GOACC_parallel_keyed): Initialize dims.
	* plugin/plugin-nvptx.c (nvptx_exec): Provide default values for
	dims.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-2.c: Adjust to
	-ftree-parallelize-loops/-fopenacc changes.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-3.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-and-seq-2.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-and-seq-3.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-and-seq-4.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-and-seq-5.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-and-seq-6.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-and-seq.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-collapse.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-g.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-mod-not-zero.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-n.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop-nest.c:
	Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-loop.c: Likewise.
	* testsuite/libgomp.oacc-c-c++-common/kernels-reduction.c:
	Likewise.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@233634 138bc75d-0d04-0410-961f-82ee72b054a4