Fix this longstanding bug that luckily did not bite us yet: Use Class.prototype.foo$bailout.call(th…

tests/language/bailout_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.
+
+// Test that a call to a bailout method in dart2js resolves to the
+// right method.
+
+var reachedAfoo = new C();
+
+class A {
+  foo() {
+    // Using '++' makes sure there is a type guard.
+    reachedAfoo++;
+  }
+}
+
+class B extends A {
+  foo() {
+    reachedAfoo++;
+    // Call the Expect method after the type guard.
+    Expect.fail('Should never reach B.foo');
+  }
+
+  bar() {
+    super.foo();
+  }
+}
+
+class C {
+  int value = 0;
+  operator +(val) {
+    value += val;
+    return this;
+  }
+}
+
+main() {
+  // Using a loop makes sure the 'foo' methods will have an optimized
+  // version.
+  while (reachedAfoo.value != 0) {
+    new A().foo();
+    new B().foo();
+  }
+  new B().bar();
+  Expect.equals(1, reachedAfoo.value);
+}