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/internal/gc/walk.go b/src/cmd/internal/gc/walk.go
index c845f78..bf91116 100644
--- a/src/cmd/internal/gc/walk.go
+++ b/src/cmd/internal/gc/walk.go
@@ -564,16 +564,16 @@
 		goto ret
 
 	case OLITERAL:
-		n.Addable = 1
+		n.Addable = true
 		goto ret
 
 	case OCLOSUREVAR, OCFUNC:
-		n.Addable = 1
+		n.Addable = true
 		goto ret
 
 	case ONAME:
 		if n.Class&PHEAP == 0 && n.Class != PPARAMREF {
-			n.Addable = 1
+			n.Addable = true
 		}
 		goto ret
 
@@ -975,7 +975,7 @@
 				l := Nod(ONAME, nil, nil)
 				l.Sym = sym
 				l.Type = Ptrto(Types[TUINT8])
-				l.Addable = 1
+				l.Addable = true
 				l.Class = PEXTERN
 				l.Xoffset = 0
 				sym.Def = l
@@ -983,7 +983,7 @@
 			}
 
 			l := Nod(OADDR, sym.Def, nil)
-			l.Addable = 1
+			l.Addable = true
 			ll = list(ll, l)
 
 			if isdirectiface(n.Left.Type) {