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/reflect.go b/src/cmd/internal/gc/reflect.go
index bd5be0f..77504fa 100644
--- a/src/cmd/internal/gc/reflect.go
+++ b/src/cmd/internal/gc/reflect.go
@@ -882,7 +882,7 @@
 		n := Nod(ONAME, nil, nil)
 		n.Sym = s
 		n.Type = Types[TUINT8]
-		n.Addable = 1
+		n.Addable = true
 		n.Ullman = 1
 		n.Class = PEXTERN
 		n.Xoffset = 0
@@ -899,7 +899,7 @@
 	s := typenamesym(t)
 	n := Nod(OADDR, s.Def, nil)
 	n.Type = Ptrto(s.Def.Type)
-	n.Addable = 1
+	n.Addable = true
 	n.Ullman = 2
 	n.Typecheck = 1
 	return n