PR debug/54970
	* cfgexpand.c (expand_debug_expr): Expand &MEM_REF[&var, n]
	as DEBUG_IMPLICIT_PTR + n if &var expands to DEBUG_IMPLICIT_PTR.
	* tree-sra.c (create_access_replacement): Allow also MEM_REFs
	with ADDR_EXPR first operand in DECL_DEBUG_EXPR expressions.
	* var-tracking.c (track_expr_p): Handle MEM_REFs in DECL_DEBUG_EXPR
	expressions.
	* dwarf2out.c (add_var_loc_to_decl): Likewise.

	PR debug/54971
	* gcc.dg/guality/pr54970.c: New test.

From-SVN: r192860