Rewrite the negative try-catch tests into a single multi test.

tests/language/src/TryCatch3NegativeTest.dart

-// Copyright (c) 2011, 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.
-// Dart test program for testing try/catch statement without any exceptions
-// being thrown.
-// Negative test should fail compilation with duplicate declaration 
-// of variable "e" in catch clause 
-
-interface TestException {
-  String getMessage();
-}
-
-class MyException implements TestException {
-  const MyException([String message = ""]) : message_ = message;
-  String getMessage() { return message_; }
-  final String message_;
-}
-
-class StackTrace {
-}
-
-class Helper {
-  static int f1(int i) {
-    try {
-      int j;
-      j = f2();
-    } catch (TestException e, StackTrace e) {
-      i = 200;
-    }
-    return i;
-  }
-
-  static int f2() {
-    return 2;
-  }
-}
-
-main() {
-  Expect.equals(1, Helper.f1(1));
-}