Dart VM: Simplify code generation for equality operators.

tests/language/vm/function_equality_vm_test.dart

+// Copyright (c) 2013, 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.
+
+// Test function equality with null.
+
+import "package:expect/expect.dart";
+
+class A {
+  foo() { }
+}
+
+main() {
+  var a = new A();
+  var f = a.foo;
+  Expect.isFalse(f == null);
+  Expect.isFalse(null == f);
+}
+