jump.c: Use rtx_insn in a few places (also touches rtl.h and cfgexpand.c)

jump.c: Use rtx_insn in a few places (also touches rtl.h and cfgexpand.c)

gcc/
	* rtl.h (rebuild_jump_labels): Strengthen param "f" from rtx to
	rtx_insn *.
	(rebuild_jump_labels_chain): Likewise for param "chain".

	* cfgexpand.c (pass_expand::execute): Add checked cast to
	rtx_insn * when calling rebuild_jump_labels_chain in region where
	we know e->insns.r is non-NULL.

	* jump.c (rebuild_jump_labels_1): Strengthen param "f" from rtx to
	rtx_insn *.
	(rebuild_jump_labels): Likewise.
	(rebuild_jump_labels_chain): Likewise for param "chain".
	(cleanup_barriers): Likewise for locals "insn", "next", "prev".
	(init_label_info): Likewise for param "f".
	(maybe_propagate_label_ref): Likewise for params "jump_insn",
	"prev_nonjump_insn".
	(mark_all_labels): Likewise for param "f" and locals "insn",
	"prev_nonjump_insn".

From-SVN: r214341