Expand oacc kernels after pass_fre

Expand oacc kernels after pass_fre

	gcc/
	* omp-low.c: Include gimple-pretty-print.h.
	(release_first_vuse_in_edge_dest): New function.
	(expand_omp_target): When not in ssa, don't split off oacc kernels
	region, clear PROP_gimple_eomp in cfun->curr_properties to force later
	expanssion, and add GOACC_kernels_internal call.
	When in ssa, split off oacc kernels and convert GOACC_kernels_internal
	into GOACC_kernels call.  Handle ssa-code.
	(pass_data_expand_omp): Don't set PROP_gimple_eomp unconditionally in
	properties_provided field.
	(pass_expand_omp::execute): Set PROP_gimple_eomp in
	cfun->curr_properties tentatively.
	(pass_data_expand_omp_ssa): Add TODO_remove_unused_locals to
	todo_flags_finish field.
	(pass_expand_omp_ssa::execute): Release dangling SSA_NAMEs after calling
	execute_expand_omp.
	(gimple_stmt_ssa_operand_references_var_p)
	(gimple_stmt_omp_data_i_init_p): New function.
	* omp-low.h (gimple_stmt_omp_data_i_init_p): Declare.
	* passes.def: Add pass_expand_omp_ssa after pass_fre.  Add
	pass_expand_omp_ssa after pass_all_early_optimizations.
	* tree-ssa-ccp.c: Include omp-low.h.
	(surely_varying_stmt_p, ccp_visit_stmt): Handle .omp_data_i init
	conservatively.
	* tree-ssa-forwprop.c: Include omp-low.h.
	(pass_forwprop::execute): Handle .omp_data_i init conservatively.
	* tree-ssa-sccvn.c: Include omp-low.h.
	(visit_use): Handle .omp_data_i init conservatively.
	* cgraph.c (cgraph_node::release_body): Don't release offloadable
	functions.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gomp-4_0-branch@222279 138bc75d-0d04-0410-961f-82ee72b054a4