Make next_insn and previous_insn require an rtx_insn *

Make next_insn and previous_insn require an rtx_insn *

gcc/
2014-08-28  David Malcolm  <dmalcolm@redhat.com>

	* rtl.h (previous_insn): Strengthen param from rtx to rtx_insn *.
	(next_insn): Likewise.
	* emit-rtl.c (next_insn): Likewise.
	(previous_insn): Likewise.
	* config/pa/pa.c (remove_useless_addtr_insns): Strenghten locals
	"insn" and "next" from rtx to rtx_insn *.
	* config/picochip/picochip.c (picochip_reorg): Likewise for locals
	"insn", "insn1", "vliw_start",  "prologue_end_note",
	"last_insn_in_packet".

From-SVN: r214708