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

tests/language/implied_interface_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.
 
 class BaseClass {
   var foo;
   BaseClass() { foo = 0; }
   toString() => "BaseClass";
 }
 
@@ skipping 16 matching lines @@
 class ImplementsExtendsClass implements ExtendsClass {
   ImplementsExtendsClass() {}
 }
 
 main() {
   ImplementsClass c1 = new ImplementsClass();
   ImplementsExtendsClass c2 = new ImplementsExtendsClass();
   try {
     c1.foo;
     Expect.fail('expected a NoSuchMethodException');
-  } catch (NoSuchMethodException ex) {
+  } on NoSuchMethodException catch (ex) {
     // Expected error.
   }
   try {
     c2.foo;
     Expect.fail('expected a NoSuchMethodException');
-  } catch (NoSuchMethodException ex) {
+  } on NoSuchMethodException catch (ex) {
     // Expected error.
   }
   Expect.equals(true, c1 is BaseClass);
   Expect.equals(true, c1 is !ExtendsClass);
   Expect.equals(true, c2 is BaseClass);
   Expect.equals(true, c2 is ExtendsClass);
   Expect.equals(true, c2 is !ImplementsClass);
   Expect.equals("BaseClass", "${new BaseClass()}");
 
   // Verify we don't inherit toString from BaseClass
   Expect.notEquals("BaseClass", "${c1}");
   Expect.notEquals("BaseClass", "${c2}");
 }