Update almost all tests (except co19) to use the new try-catch syntax.

tests/language/method_invocation_test.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.
 
 // Testing method invocation.
 // Currently testing only NullPointerException.
 
 class A {
   A() {}
   int foo() {
     return 1;
   }
 }
 
 class MethodInvocationTest {
   static void testNullReceiver() {
     A a = new A();
     Expect.equals(1, a.foo());
     a = null;
     bool exceptionCaught = false;
     try {
       a.foo();
-    } catch (NullPointerException e) {
+    } on NullPointerException catch (e) {
       exceptionCaught = true;
     }
     Expect.equals(true, exceptionCaught);
   }
 
   static void testMain() {
     testNullReceiver();
   }
 }
 
 main() {
   MethodInvocationTest.testMain();
 }