re PR debug/50317 (missing DW_OP_GNU_implicit_pointer)

re PR debug/50317 (missing DW_OP_GNU_implicit_pointer)

	PR debug/50317
	* tree-ssa.c (target_for_debug_bind): Also allow is_gimple_reg_type
	vars that aren't referenced.
	(tree-ssa-live.c (remove_unused_locals): Don't clear TREE_ADDRESSABLE
	of unreferenced local vars.
	* cfgexpand.c (expand_debug_expr): For DEBUG_IMPLICIT_PTR allow also
	TREE_ADDRESSABLE vars that satisfy target_for_debug_bind.

From-SVN: r181971