Fix VM memory allocation optimizations by reducing what we allocate on the heap

internal/builtins/read.go

@@ -24,10 +24,10 @@ func Read(args ...object.Object) object.Object {
 		n  = DefaultBufferSize
 	)
 
-	fd = int(args[0].(*object.Integer).Value)
+	fd = int(args[0].(object.Integer).Value)
 
 	if len(args) == 2 {
-		n = int(args[1].(*object.Integer).Value)
+		n = int(args[1].(object.Integer).Value)
 	}
 
 	buf := make([]byte, n)
@@ -36,5 +36,5 @@ func Read(args ...object.Object) object.Object {
 		return newError("IOError: %s", err)
 	}
 
-	return &object.String{Value: string(buf[:n])}
+	return object.String{Value: string(buf[:n])}
 }