PR debug/47283
	* cfgexpand.c (expand_debug_expr) <case MEM_REF>: If MEM_REF
	first operand is not is_gimple_mem_ref_addr, try to fold it.
	If the operand still isn't is_gimple_mem_ref_addr, clear
	MEM_EXPR on op0.

From-SVN: r170654