cmd/internal/gc: make Node.Needzero a bool

Node.Needzero only has two values and acts as a bool, so make it a bool.

Change-Id: Ica46e5ebafbe478017ea52ce6bb335f404059677
Reviewed-on: https://go-review.googlesource.com/6800Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/cmd/5g/ggen.go

@@ -30,7 +30,7 @@ func defframe(ptxt *obj.Prog) {
 	r0 := uint32(0)
 	for l := gc.Curfn.Dcl; l != nil; l = l.Next {
 		n = l.N
-		if n.Needzero == 0 {
+		if !n.Needzero {
 			continue
 		}
 		if n.Class != gc.PAUTO {

src/cmd/6g/ggen.go

@@ -32,7 +32,7 @@ func defframe(ptxt *obj.Prog) {
 	// iterate through declarations - they are sorted in decreasing xoffset order.
 	for l := gc.Curfn.Dcl; l != nil; l = l.Next {
 		n = l.N
-		if n.Needzero == 0 {
+		if !n.Needzero {
 			continue
 		}
 		if n.Class != gc.PAUTO {

src/cmd/8g/ggen.go

@@ -30,7 +30,7 @@ func defframe(ptxt *obj.Prog) {
 	ax := uint32(0)
 	for l := gc.Curfn.Dcl; l != nil; l = l.Next {
 		n = l.N
-		if n.Needzero == 0 {
+		if !n.Needzero {
 			continue
 		}
 		if n.Class != gc.PAUTO {

src/cmd/9g/ggen.go

@@ -32,7 +32,7 @@ func defframe(ptxt *obj.Prog) {
 	// iterate through declarations - they are sorted in decreasing xoffset order.
 	for l := gc.Curfn.Dcl; l != nil; l = l.Next {
 		n = l.N
-		if n.Needzero == 0 {
+		if !n.Needzero {
 			continue
 		}
 		if n.Class != gc.PAUTO {

src/cmd/internal/gc/go.go

@@ -174,7 +174,7 @@ type Node struct {
 	Reslice        uint8
 	Likely         int8
 	Hasbreak       uint8
-	Needzero       uint8
+	Needzero       bool
 	Needctxt       bool
 	Esc            uint
 	Funcdepth      int

src/cmd/internal/gc/pgen.go

@@ -211,8 +211,8 @@ func cmpstackvar(a *Node, b *Node) int {
 		return bp - ap
 	}
 
-	ap = int(a.Needzero)
-	bp = int(b.Needzero)
+	ap = bool2int(a.Needzero)
+	bp = bool2int(b.Needzero)
 	if ap != bp {
 		return bp - ap
 	}

src/cmd/internal/gc/plive.go

@@ -1255,8 +1255,8 @@ func livenessepilogue(lv *Liveness) {
 						}
 						bvset(all, pos) // silence future warnings in this block
 						n = lv.vars[pos]
-						if n.Needzero == 0 {
-							n.Needzero = 1
+						if !n.Needzero {
+							n.Needzero = true
 							if debuglive >= 1 {
 								Warnl(int(p.Lineno), "%v: %v is ambiguously live", Nconv(Curfn.Nname, 0), Nconv(n, obj.FmtLong))
 							}