Fix a bug where we would emit a noSuchMethod handler in the Object class for Object methods because…

tests/language/no_such_method_empty_selector_test.dart

Index: tests/language/no_such_method_empty_selector_test.dart
===================================================================
--- tests/language/no_such_method_empty_selector_test.dart	(revision 0)
+++ tests/language/no_such_method_empty_selector_test.dart	(revision 0)
@@ -0,0 +1,34 @@
+// 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.
+
+import "package:expect/expect.dart";
+
+class A {
+  noSuchMethod(_) => 'foo';
+  get hashCode => 42;
+}
+
+// Keep that list empty to make the inferrer infer an empty element
+// type.
+var a = [];
+var b = [new A(), new Object()];
+
+main() {
+  // The following [hashCode] call will create a selector whose
+  // receiver type is empty. This used to make dart2js generate a
+  // [noSuchMethod] handler for [hashCode] on the Object class, which
+  // would override the actual implementation.
+  Expect.throws(() => a[0].hashCode, (e) => e is RangeError);
+
+  // This code calls the [hashCode] method put on the [Object] class,
+  // which used to be a [noSuchMethod] handler method.
+  Expect.isTrue(b[1].hashCode is int);
+
+  // Sanity checks.
+  Expect.equals(42, b[0].hashCode);
+  Expect.equals('foo', b[0].foo());
+
+  // Prevent optimizations on the [b] variable.
+  b.clear();
+}