PR debug/45003
	* var-tracking.c (reverse_op): Also handle {SIGN,ZERO}_EXTEND of
	a MEM.
	* dwarf2out.c (loc_descriptor): Don't handle SIGN_EXTEND nor
	ZERO_EXTEND here.

	* gcc.dg/guality/pr45003-2.c: New test.
	* gcc.dg/guality/pr45003-3.c: New test.

From-SVN: r162364