PR rtl-optimization/49941
	* jump.c (mark_jump_label): Comment.
	(mark_jump_label_1): Set JUMP_LABEL for return jumps.
	* emit-rtl.c (copy_rtx_if_shared_1, copy_insn_1): Leave RETURN shared.
	(mark_used_flags): Don't mark RETURN.

From-SVN: r177268