code review 901042: exp/eval: Fix example and add target to Makefile

src/pkg/exp/eval/main.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 main
 
 import (
+        "bufio"
         "exp/eval"
-        "bufio"
         "flag"
         "go/parser"
         "go/scanner"
         "io/ioutil"
         "os"
 )
 
 var filename = flag.String("f", "", "file to run")
 
 func main() {
@@ skipping 62 matching lines @@
                 v, err := code.Run()
                 if err != nil {
                         println(err.String())
                         continue
                 }
                 if v != nil {
                         println(v.String())
                 }
         }
 }