* lto.c (hash_canonical_type): Be sure we hash only types that
	need alias set.
	(gimple_register_canonical_type_1): Do not produce canonical
	types for types that do not need alias sets.
	* tree.c (gimple_canonical_types_compatible_p): Sanity check that
	we do not try to compute canonical type for type that does not need
	alias set.
	(verify_type): Drop FIXME for METHOD_TYPE, update FIXME for
	FUNCITON_TYPE.
	* tree.h (type_with_alias_set_p): New.

From-SVN: r223608