PR c++/86485 - simple_empty_class_p

Yet another tweak that would have fixed this bug: we should treat INIT_EXPR
and MODIFY_EXPR differently for determining whether this is a simple empty
class copy, since a TARGET_EXPR on the RHS is direct initialization if
INIT_EXPR but copy if MODIFY_EXPR.

	* cp-gimplify.c (simple_empty_class_p): Also true for MODIFY_EXPR.

From-SVN: r271521