cmd/internal/gc: convert yet more Node fields to bools

Convert Embedded, Method, and Colas to bools.

I believe that this is the last of the Node fields
that can be trivially converted to bools.

No functional changes. Passes toolstash -cmp.

Change-Id: I81962ee47866596341fc60d24d6959c20cd7fc1c
Reviewed-on: https://go-review.googlesource.com/8440
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
diff --git a/src/cmd/8g/cgen.go b/src/cmd/8g/cgen.go
index 5546aba3..0b93694 100644
--- a/src/cmd/8g/cgen.go
+++ b/src/cmd/8g/cgen.go
@@ -17,7 +17,7 @@
  */
 func igenindex(n *gc.Node, res *gc.Node, bounded bool) *obj.Prog {
 	if !gc.Is64(n.Type) {
-		if n.Addable != 0 {
+		if n.Addable {
 			// nothing to do.
 			*res = *n
 		} else {
@@ -58,13 +58,13 @@
 	gc.Tempname(&tsrc, gc.Types[gc.Tptr])
 	var tdst gc.Node
 	gc.Tempname(&tdst, gc.Types[gc.Tptr])
-	if n.Addable == 0 {
+	if !n.Addable {
 		gc.Agen(n, &tsrc)
 	}
-	if res.Addable == 0 {
+	if !res.Addable {
 		gc.Agen(res, &tdst)
 	}
-	if n.Addable != 0 {
+	if n.Addable {
 		gc.Agen(n, &src)
 	} else {
 		gmove(&tsrc, &src)
@@ -74,7 +74,7 @@
 		gc.Gvardef(res)
 	}
 
-	if res.Addable != 0 {
+	if res.Addable {
 		gc.Agen(res, &dst)
 	} else {
 		gmove(&tdst, &dst)
diff --git a/src/cmd/8g/cgen64.go b/src/cmd/8g/cgen64.go
index ee04bdb..7fb6549 100644
--- a/src/cmd/8g/cgen64.go
+++ b/src/cmd/8g/cgen64.go
@@ -63,14 +63,14 @@
 
 	l := n.Left
 	r := n.Right
-	if l.Addable == 0 {
+	if !l.Addable {
 		var t1 gc.Node
 		gc.Tempname(&t1, l.Type)
 		gc.Cgen(l, &t1)
 		l = &t1
 	}
 
-	if r != nil && r.Addable == 0 {
+	if r != nil && !r.Addable {
 		var t2 gc.Node
 		gc.Tempname(&t2, r.Type)
 		gc.Cgen(r, &t2)
diff --git a/src/cmd/8g/ggen.go b/src/cmd/8g/ggen.go
index a4a373c..115c962 100644
--- a/src/cmd/8g/ggen.go
+++ b/src/cmd/8g/ggen.go
@@ -637,7 +637,7 @@
 		// binary
 		if nl.Ullman >= nr.Ullman {
 			gc.Cgen(nl, &f0)
-			if nr.Addable != 0 {
+			if nr.Addable {
 				gins(foptoas(int(n.Op), n.Type, 0), nr, &f0)
 			} else {
 				gc.Cgen(nr, &f0)
@@ -645,7 +645,7 @@
 			}
 		} else {
 			gc.Cgen(nr, &f0)
-			if nl.Addable != 0 {
+			if nl.Addable {
 				gins(foptoas(int(n.Op), n.Type, Frev), nl, &f0)
 			} else {
 				gc.Cgen(nl, &f0)
@@ -762,14 +762,14 @@
 	var n2 gc.Node
 	var ax gc.Node
 	if !gc.Thearch.Use387 {
-		if nl.Addable == 0 {
+		if !nl.Addable {
 			var n1 gc.Node
 			gc.Tempname(&n1, nl.Type)
 			gc.Cgen(nl, &n1)
 			nl = &n1
 		}
 
-		if nr.Addable == 0 {
+		if !nr.Addable {
 			var tmp gc.Node
 			gc.Tempname(&tmp, nr.Type)
 			gc.Cgen(nr, &tmp)
diff --git a/src/cmd/8g/gsubr.go b/src/cmd/8g/gsubr.go
index 929cbae..76c67af 100644
--- a/src/cmd/8g/gsubr.go
+++ b/src/cmd/8g/gsubr.go
@@ -1732,7 +1732,7 @@
 	var oary [10]int64
 	var nn *gc.Node
 	o := gc.Dotoffset(n, oary[:], &nn)
-	if nn != nil && nn.Addable != 0 && o == 1 && oary[0] >= 0 {
+	if nn != nil && nn.Addable && o == 1 && oary[0] >= 0 {
 		*n1 = *nn
 		n1.Type = n.Type
 		n1.Xoffset += oary[0]