* typeck.c (build_class_member_access_expr): Move
	-Winvalid-offsetof code...
	* semantics.c (finish_offsetof): ...here.
	* parser.c (cp_parser_builtin_offsetof): Remember the location of
	the type argument.
	* pt.c (tsubst_copy_and_build) [OFFSETOF_EXPR]: Preserve it.

From-SVN: r215070