ddg: Use rtx_insn

ddg: Use rtx_insn

gcc/
	* ddg.h (struct ddg_node): Strengthen fields "insn" and
	"first_note" from rtx to rtx_insn *.
	(get_node_of_insn): Likewise for param 2 "insn".
	(autoinc_var_is_used_p): Likewise for params "def_insn" and "use_insn".

	* ddg.c (mem_read_insn_p): Strengthen param "insn" from rtx to
	rtx_insn *.
	(mem_write_insn_p): Likewise.
	(mem_access_insn_p): Likewise.
	(autoinc_var_is_used_p): Likewise for params "def_insn" and "use_insn".
	(def_has_ccmode_p): Likewise for param "insn".
	(add_cross_iteration_register_deps): Likewise for locals
	"def_insn" and "use_insn".
	(insns_may_alias_p): Likewise for params "insn1" and "insn2".
	(build_intra_loop_deps): Likewise for local "src_insn".
	(create_ddg): Strengthen locals "insn" and "first_note" from rtx
	to rtx_insn *.
	(get_node_of_insn): Likewise for param "insn".

From-SVN: r214317