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

tests/language/named_parameters4_negative_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.
 // Dart test program for testing named parameters.
 
 
 class NamedParameters4NegativeTest {
 
   static int F31(int a, [int b = 20, int c = 30]) {
     return 100*(100*a + b) + c;
   }
 
   static testMain() {
     try {
       F31(10, b:25, b:35);  // Duplicate named argument.
-    } catch (var e) {
+    } catch (e) {
       // This is a negative test that should not compile.
       // If it runs due to a bug, catch and ignore exceptions.
     }
   }
 }
 
 main() {
   NamedParameters4NegativeTest.testMain();
 }