Remove function names on function expressions.

tests/compiler/dart2js_extra/closure_capture5_test.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import "package:expect/expect.dart";
 
 closure0() {
   var fs = [];
   for (var x = 1; x <= 3; x++) {
-    fs.add(fun() { return x; });
+    fs.add(() { return x; });
   }
   Expect.equals(3, fs.length);
   Expect.equals(1, fs[0]());
   Expect.equals(2, fs[1]());
   Expect.equals(3, fs[2]());
 }
 
 closure1() {
   var fs = [];
   for (var x = 0; x < 6; x++) {
-    fs.add(fun() { return x; });
+    fs.add(() { return x; });
     x++;
   }
   Expect.equals(3, fs.length);
   Expect.equals(1, fs[0]());
   Expect.equals(3, fs[1]());
   Expect.equals(5, fs[2]());
 }
 
 closure2() {
   var input = [1, 2, 3];
   var fs = [];
   for (var i = 0; i < input.length; i++) {
-    fs.add(fun() { return input[i]; });
+    fs.add(() { return input[i]; });
   }
   Expect.equals(3, fs.length);
   Expect.equals(1, fs[0]());
   Expect.equals(2, fs[1]());
   Expect.equals(3, fs[2]());
 }
 
 closure3() {
   var fs = [];
   for (var i = 0;
        i < 3;
-       (f() {
-         fs.add(g() => i);
+       (() {
+         fs.add(() => i);
          i++;
        })()) {
     i++;
   }
   Expect.equals(2, fs.length);
   Expect.equals(3, fs[0]());
   Expect.equals(4, fs[1]());
 }
 
 closure4() {
   var g;
   for (var i = 0;
-       (f() {
-         g = fun() => i;
+       (() {
+         g = () => i;
          return false;
        })();
        i++){
     Expect.equals(false, true);
   }
   Expect.equals(0, g());
 }
 
 main() {
   closure0();
   closure1();
   closure2();
   closure3();
   closure4();
 }