Strengthen return types of various {next|prev}_*insn from rtx to rtx_insn *

Strengthen return types of various {next|prev}_*insn from rtx to rtx_insn *

2014-08-19  David Malcolm  <dmalcolm@redhat.com>

	* rtl.h (previous_insn): Strengthen return type from rtx to
	rtx_insn *.
	(next_insn): Likewise.
	(prev_nonnote_insn): Likewise.
	(prev_nonnote_insn_bb): Likewise.
	(next_nonnote_insn): Likewise.
	(next_nonnote_insn_bb): Likewise.
	(prev_nondebug_insn): Likewise.
	(next_nondebug_insn): Likewise.
	(prev_nonnote_nondebug_insn): Likewise.
	(next_nonnote_nondebug_insn): Likewise.
	(prev_real_insn): Likewise.
	(next_real_insn): Likewise.
	(prev_active_insn): Likewise.
	(next_active_insn): Likewise.

	* emit-rtl.c (next_insn): Strengthen return type from rtx to
	rtx_insn *, adding a checked cast.
	(previous_insn): Likewise.
	(next_nonnote_insn): Likewise.
	(next_nonnote_insn_bb): Likewise.
	(prev_nonnote_insn): Likewise.
	(prev_nonnote_insn_bb): Likewise.
	(next_nondebug_insn): Likewise.
	(prev_nondebug_insn): Likewise.
	(next_nonnote_nondebug_insn): Likewise.
	(prev_nonnote_nondebug_insn): Likewise.
	(next_real_insn): Likewise.
	(prev_real_insn): Likewise.
	(next_active_insn): Likewise.
	(prev_active_insn): Likewise.

	* config/sh/sh-protos.h (sh_find_set_of_reg): Convert function ptr
	param "stepfunc" so that it returns an rtx_insn * rather than an
	rtx, to track the change to prev_nonnote_insn_bb, which is the
	only function this is called with.
	* config/sh/sh.c (sh_find_set_of_reg): Likewise.

From-SVN: r214178