tree-ssa-sccvn.h (struct vn_phi_s): Make phiargs member a trailing array.

tree-ssa-sccvn.h (struct vn_phi_s): Make phiargs member a trailing array.

2018-07-19  Richard Biener  <rguenther@suse.de>

	* tree-ssa-sccvn.h (struct vn_phi_s): Make phiargs member
	a trailing array.
	* tree-ssa-sccvn.c: Remove alloc-pool.h use.
	(vn_phi_hasher): Derive from nofree_ptr_hash and remove remove method.
	(vn_reference_hasher): Likewise.
	(struct vn_tables_s): Remove obstack and alloc-pool members.
	(vn_tables_obstack, vn_tables_insert_obstack): New global obstacks.
	(vn_nary_build_or_lookup_1): Manually build in vn_tables_insert_obstack.
	(vn_reference_insert): Allocate from obstack instead of from alloc-pool.
	(vn_reference_insert_pieces): Likewise.
	(alloc_vn_nary_op_noinit): Adjust.
	(vn_nary_op_insert_stmt): Allocate phiargs in-place.
	(vn_phi_eq): Adjust.
	(shared_lookup_phiargs): Remove.
	(vn_phi_lookup): Allocate temporary vn_phi_s on the stack.
	(vn_phi_insert): Allocate from obstack instead of from alloc-pool.
	(visit_reference_op_call): Likewise.
	(copy_nary, copy_phi, copy_reference): Remove.
	(process_scc): Rewind the obstack when iterating.  Do not
	copy the elements to valid_info but just move them from one
	hashtable to the other.
	(allocate_vn_table): Adjust.
	(free_vn_table): Likewise.
	(init_scc_vn): Likewise.
	(free_scc_vn): Likewise.

From-SVN: r262879