except.*: Use rtx_insn (also touches function.h)

except.*: Use rtx_insn  (also touches function.h)

gcc/
	* except.h (sjlj_emit_function_exit_after): Strengthen param
	"after" from rtx to rtx_insn *.  This is only called with
	result of get_last_insn (in function.c) so type-change should be
	self-contained.

	* function.h (struct rtl_eh): Strengthen field "ehr_label" from
	rtx to rtx_code_label *, and field "sjlj_exit_after" from rtx
	to rtx_insn *.  These fields are only used from except.c so this
	type-change should be self-contained to this patch.

	* except.c (emit_to_new_bb_before): Strengthen param "seq" and
	local "last" from rtx to rtx_insn *.
	(dw2_build_landing_pads): Likewise for local "seq".
	(sjlj_mark_call_sites): Likewise for locals "insn", "before", p".
	(sjlj_emit_function_enter): Strengthen param "dispatch_label" from
	rtx to rtx_code_label *.  Strengthen locals "fn_begin", "seq" from
	rtx to rtx_insn *.
	(sjlj_emit_function_exit_after): Strengthen param "after" from rtx
	to rtx_insn *.
	(sjlj_emit_function_exit): Likewise for locals "seq", "insn".
	(sjlj_emit_dispatch_table): Likewise for locals "seq", "seq2".
	(sjlj_build_landing_pads): Replace NULL_RTX with NULL when
	referring to an insn.  Strengthen local "dispatch_label" from
	rtx to rtx_code_label *.
	(set_nothrow_function_flags): Strengthen local "insn" from rtx to
	rtx_insn *.
	(expand_eh_return): Strengthen local "around_label" from
	rtx to rtx_code_label *.
	(convert_to_eh_region_ranges): Strengthen locals "iter",
	"last_action_insn", "first_no_action_insn",
	"first_no_action_insn_before_switch",
	"last_no_action_insn_before_switch", from rtx to rtx_insn *.

From-SVN: r214321