re PR middle-end/65680 (ICE at -O1 and above on x86_64-linux-gnu in expand_assignment, at expr.c:4830)

	PR middle-end/65680
	* expr.c (get_inner_reference): Handle bit_offset that doesn't fit
	into signed HOST_WIDE_INT the same as negative bit_offset.

	* gcc.c-torture/compile/pr65680.c: New test.

From-SVN: r221899