re PR sanitizer/63788 (ICE: SIGSEGV in contains_struct_check with -O -fsanitize=undefined on almost any fortran code)

	PR sanitizer/63788
	* asan.c (initialize_sanitizer_builtins): Add BT_FN_SIZE_CONST_PTR_INT
	var.  Conditionally build BUILT_IN_OBJECT_SIZE decl.
	(ATTR_PURE_NOTHROW_LEAF_LIST): Define.

From-SVN: r218084