* lto.c (iterative_hash_canonical_type): Always recurse for pointers.

	* lto.c (iterative_hash_canonical_type): Always recurse for pointers.
	(gimple_register_canonical_type_1): Check that pointers do not get
	canonical types.
	(gimple_register_canonical_type): Do not register pointers.

	* tree.c (build_pointer_type_for_mode,build_reference_type_for_mode):
	In LTO we do not compute TYPE_CANONICAL of pointers.
	(gimple_canonical_types_compatible_p): Improve coments; sanity check
	that pointers do not have canonical type that would make us believe
	they are different.
	* alias.c (get_alias_set): Do structural type equality on pointers;
	enable pointer path for LTO; also glob pointer to vector with pointer
	to vector element; glob pointers and references for LTO; do more strict
	sanity checking about build_pointer_type returning the canonical type
	which is also the main variant.
	(record_component_aliases): When component type is pointer and we
	do LTO; record void_type_node alias set.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@230715 138bc75d-0d04-0410-961f-82ee72b054a4