PR debug/55730
	* dwarf2out.c (mem_loc_descriptor): Ignore CLOBBER.
	* valtrack.c (gen_lowpart_for_debug): New function.
	(propagate_for_debug): Temporarily set rtl_hooks.gen_lowpart_no_emit
	to gen_lowpart_for_debug.

	* gcc.dg/debug/pr55730.c: New test.

From-SVN: r194607