cmd/6g: fix warnings on Plan 9

src/cmd/6g/peep.c:471 set and not used: r
src/cmd/6g/peep.c:560 overspecified class: regconsttyp GLOBL STATIC
src/cmd/6g/peep.c:761 more arguments than format IND STRUCT Prog
src/cmd/6g/reg.c:185 set and not used: r1
src/cmd/6g/reg.c:786 format mismatch d VLONG, arg 3
src/cmd/6g/reg.c:1064 format mismatch d VLONG, arg 5

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/8197044

src/cmd/6g/peep.c

@@ -472,6 +472,7 @@ elimshortmov(Reg *r)
 {
 	Prog *p;
 
+	USED(r);
 	for(r=firstr; r!=R; r=r->link) {
 		p = r->prog;
 		if(regtyp(&p->to)) {
@@ -555,7 +556,7 @@ elimshortmov(Reg *r)
 	}
 }
 
-int
+static int
 regconsttyp(Adr *a)
 {
 	if(regtyp(a))
@@ -758,7 +759,7 @@ subprop(Reg *r0)
 		}
 	}
 	if(debug['P'] && debug['v'])
-		print("\tran off end; return 0\n", p);
+		print("\tran off end; return 0\n");
 	return 0;
 
 gotit:

src/cmd/6g/reg.c

@@ -182,7 +182,6 @@ regopt(Prog *firstp)
 		return;
 	}
 
-	r1 = R;
 	firstr = R;
 	lastr = R;
 
@@ -783,7 +782,7 @@ brk:
 				Var *v;
 
 				v = var + rgp->varno;
-				print("registerize %N+%d (bit=%2d et=%2E) in %R\n",
+				print("registerize %N+%lld (bit=%2d et=%2E) in %R\n",
 						v->node, v->offset, rgp->varno, v->etype, rgp->regno);
 			}
 			paint3(rgp->enter, rgp->varno, vreg, rgp->regno);
@@ -1061,7 +1060,7 @@ mkvar(Reg *r, Adr *a)
 	v->node = node;
 
 	if(debug['R'])
-		print("bit=%2d et=%2E w=%d+%d %#N %D flag=%d\n", i, et, o, w, node, a, v->addr);
+		print("bit=%2d et=%2E w=%d+%lld %#N %D flag=%d\n", i, et, o, w, node, a, v->addr);
 
 	ostats.nvar++;