PR rtl-optimization/65401
	* combine.c (rtx_equal_for_field_assignment_p): Add widen_x
	argument.  If true, adjust_address_nv of x with big-endian
	correction for the mode widening to GET_MODE (y).
	(make_field_assignment): Don't do MEM mode widening here.
	Use MEM_P instead of GET_CODE == MEM.

	* gcc.c-torture/execute/pr65401.c: New test.

From-SVN: r221433