fix build again; this time for sure.

(this time i ran g4 nothave)

TBR=r
OCL=29156
CL=29156

src/lib/hash/hash.go

+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package hash
+
+import "io";
+
+// Hash is the common interface implemented by all hash functions.
+// The Write method never returns an error.
+// Sum returns the bytes of integer hash codes in big-endian order.
+type Hash interface {
+	io.Writer;
+	Sum() []byte;
+	Reset();
+	Size() int;	// number of bytes Sum returns
+}
+
+// Hash32 is the common interface implemented by all 32-bit hash functions.
+type Hash32 interface {
+	Hash;
+	Sum32() uint32;
+}
+