[dev.cc] cmd/5g,cmd/6g,cmd/9g: fix warnings on Plan 9

warning: src/cmd/5g/reg.c:461 format mismatch d VLONG, arg 5
warning: src/cmd/6g/reg.c:396 format mismatch d VLONG, arg 5
warning: src/cmd/9g/reg.c:440 format mismatch d VLONG, arg 5

LGTM=minux
R=rsc, minux
CC=golang-codereviews
https://golang.org/cl/179300043

src/cmd/5g/reg.c

@@ -458,7 +458,7 @@ brk:
 		print("\nregisterizing\n");
 	for(i=0; i<nregion; i++) {
 		if(debug['R'] && debug['v'])
-			print("region %d: cost %d varno %d enter %d\n", i, rgp->cost, rgp->varno, rgp->enter->f.prog->pc);
+			print("region %d: cost %d varno %d enter %lld\n", i, rgp->cost, rgp->varno, rgp->enter->f.prog->pc);
 		bit = blsh(rgp->varno);
 		vreg = paint2(rgp->enter, rgp->varno, 0);
 		vreg = allreg(vreg, rgp);

src/cmd/6g/reg.c

@@ -393,7 +393,7 @@ brk:
 		print("\nregisterizing\n");
 	for(i=0; i<nregion; i++) {
 		if(debug['R'] && debug['v'])
-			print("region %d: cost %d varno %d enter %d\n", i, rgp->cost, rgp->varno, rgp->enter->f.prog->pc);
+			print("region %d: cost %d varno %d enter %lld\n", i, rgp->cost, rgp->varno, rgp->enter->f.prog->pc);
 		bit = blsh(rgp->varno);
 		vreg = paint2(rgp->enter, rgp->varno, 0);
 		vreg = allreg(vreg, rgp);

src/cmd/9g/reg.c

@@ -437,7 +437,7 @@ brk:
 		print("\nregisterizing\n");
 	for(i=0; i<nregion; i++) {
 		if(debug['R'] && debug['v'])
-			print("region %d: cost %d varno %d enter %d\n", i, rgp->cost, rgp->varno, rgp->enter->f.prog->pc);
+			print("region %d: cost %d varno %d enter %lld\n", i, rgp->cost, rgp->varno, rgp->enter->f.prog->pc);
 		bit = blsh(rgp->varno);
 		usedreg = paint2(rgp->enter, rgp->varno, 0);
 		vreg = allreg(usedreg, rgp);