cmd/{5,6,8,9}g, cmd/internal/gc: use bools for is* and okfor*

No functional changes.

This diff was generated as follows:

* Manually edit cmd/internal/gc/go.go to update types and group variables.
* Manually edit initialization in cmd/internal/gc/align.go--localized s/1/true.
* Manually fix the handling of sign in cmd/internal/gc/walk.go in func bounded (near line 4000).
* Manually update go.y and regenerate y.go.
* Run gofmt -r many times to do the rest, using https://gist.github.com/josharian/0f61dbb2dff81f938e70.

toolstash -cmp on the stdlib comes back green.

Change-Id: I19766ed551714e51b325133e7138818d117b3a9a
Reviewed-on: https://go-review.googlesource.com/6530
Reviewed-by: Russ Cox <rsc@golang.org>
diff --git a/src/cmd/internal/gc/dcl.go b/src/cmd/internal/gc/dcl.go
index ceececd..0eef37b 100644
--- a/src/cmd/internal/gc/dcl.go
+++ b/src/cmd/internal/gc/dcl.go
@@ -778,14 +778,14 @@
 		return
 	}
 
-	if t.Sym == nil && Isptr[t.Etype] != 0 {
+	if t.Sym == nil && Isptr[t.Etype] {
 		t = t.Type
 		if t.Etype == TINTER {
 			Yyerror("embedded type cannot be a pointer to interface")
 		}
 	}
 
-	if Isptr[t.Etype] != 0 {
+	if Isptr[t.Etype] {
 		Yyerror("embedded type cannot be a pointer")
 	} else if t.Etype == TFORW && t.Embedlineno == 0 {
 		t.Embedlineno = lineno
@@ -1178,7 +1178,7 @@
 		return false
 	}
 	t := rcvr.Type
-	if Isptr[t.Etype] == 0 {
+	if !Isptr[t.Etype] {
 		return false
 	}
 	t = t.Type
@@ -1241,7 +1241,7 @@
 		goto bad
 	}
 	s = t.Sym
-	if s == nil && Isptr[t.Etype] != 0 {
+	if s == nil && Isptr[t.Etype] {
 		t = t.Type
 		if t == nil {
 			goto bad
@@ -1269,13 +1269,13 @@
 	}
 
 	if (spkg == nil || nsym.Pkg != spkg) && !exportname(nsym.Name) {
-		if t0.Sym == nil && Isptr[t0.Etype] != 0 {
+		if t0.Sym == nil && Isptr[t0.Etype] {
 			p = fmt.Sprintf("(%v).%s.%s%s", Tconv(t0, obj.FmtLeft|obj.FmtShort), nsym.Pkg.Prefix, nsym.Name, suffix)
 		} else {
 			p = fmt.Sprintf("%v.%s.%s%s", Tconv(t0, obj.FmtLeft|obj.FmtShort), nsym.Pkg.Prefix, nsym.Name, suffix)
 		}
 	} else {
-		if t0.Sym == nil && Isptr[t0.Etype] != 0 {
+		if t0.Sym == nil && Isptr[t0.Etype] {
 			p = fmt.Sprintf("(%v).%s%s", Tconv(t0, obj.FmtLeft|obj.FmtShort), nsym.Name, suffix)
 		} else {
 			p = fmt.Sprintf("%v.%s%s", Tconv(t0, obj.FmtLeft|obj.FmtShort), nsym.Name, suffix)
@@ -1358,7 +1358,7 @@
 			return
 		}
 		if t != nil {
-			if Isptr[t.Etype] != 0 {
+			if Isptr[t.Etype] {
 				if t.Sym != nil {
 					Yyerror("invalid receiver type %v (%v is a pointer type)", Tconv(pa, 0), Tconv(t, 0))
 					return
@@ -1375,7 +1375,7 @@
 				return
 			}
 
-			if Isptr[t.Etype] != 0 {
+			if Isptr[t.Etype] {
 				Yyerror("invalid receiver type %v (%v is a pointer type)", Tconv(pa, 0), Tconv(t, 0))
 				return
 			}