OpenMP/PTX privatization in SIMD regions

	* config/nvptx/nvptx-protos.h (nvptx_output_simt_enter): Declare.
	(nvptx_output_simt_exit): Declare.
	* config/nvptx/nvptx.c (nvptx_init_unisimt_predicate): Use
	cfun->machine->unisimt_location.  Handle NULL unisimt_predicate.
	(init_softstack_frame): Move initialization of crtl->is_leaf to...
	(nvptx_declare_function_name): ...here.  Emit declaration of local
	memory space buffer for omp_simt_enter insn.
	(nvptx_output_unisimt_switch): New.
	(nvptx_output_softstack_switch): New.
	(nvptx_output_simt_enter): New.
	(nvptx_output_simt_exit): New.
	* config/nvptx/nvptx.h (struct machine_function): New fields
	has_simtreg, unisimt_location, simt_stack_size, simt_stack_align.
	* config/nvptx/nvptx.md (UNSPECV_SIMT_ENTER): New unspec.
	(UNSPECV_SIMT_EXIT): Ditto.
	(omp_simt_enter_insn): New insn.
	(omp_simt_enter): New expansion.
	(omp_simt_exit): New insn.
	* config/nvptx/nvptx.opt (msoft-stack-reserve-local): New option.

	* internal-fn.c (expand_GOMP_SIMT_ENTER): New.
	(expand_GOMP_SIMT_ENTER_ALLOC): New.
	(expand_GOMP_SIMT_EXIT): New.
	* internal-fn.def (GOMP_SIMT_ENTER): New internal function.
	(GOMP_SIMT_ENTER_ALLOC): Ditto.
	(GOMP_SIMT_EXIT): Ditto.
	* target-insns.def (omp_simt_enter): New insn.
	(omp_simt_exit): Ditto.
	* omp-low.c (struct omplow_simd_context): New fields simt_eargs,
	simt_dlist.
	(lower_rec_simd_input_clauses): Implement SIMT privatization.
	(lower_rec_input_clauses): Likewise.
	(lower_lastprivate_clauses): Handle SIMT privatization.

	* omp-offload.c: Include langhooks.h, tree-nested.h, stor-layout.h.
	(ompdevlow_adjust_simt_enter): New.
	(find_simtpriv_var_op): New.
	(execute_omp_device_lower): Handle IFN_GOMP_SIMT_ENTER,
	IFN_GOMP_SIMT_ENTER_ALLOC, IFN_GOMP_SIMT_EXIT.

	* tree-inline.h (struct copy_body_data): New field dst_simt_vars.
	* tree-inline.c (expand_call_inline): Handle SIMT privatization.
	(copy_decl_for_dup_finish): Ditto.

	* tree-ssa.c (execute_update_addresses_taken): Handle GOMP_SIMT_ENTER.

From-SVN: r246550