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

tests/language/arithmetic_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.
 // Dart test program to test arithmetic operations.
 
 #library('arithmetic_test');
 #import('dart:math');
 
 class ArithmeticTest {
 
   static bool exceptionCaughtParseInt(String s) {
     try {
       parseInt(s);
       return false;
-    } catch (FormatException e) {
+    } on FormatException catch (e) {
       return true;
     }
   }
 
   static bool exceptionCaughtParseDouble(String s) {
     try {
       parseDouble(s);
       return false;
-    } catch (FormatException e) {
+    } on FormatException catch (e) {
       return true;
     }
   }
 
   static bool toIntThrowsFormatException(String str) {
     // No exception allowed for parse double.
     double d = parseDouble(str);
     try {
       var a = d.toInt();
       return false;
-    } catch (FormatException e) {
+    } on FormatException catch (e) {
       return true;
     }
   }
 
   static runOne() {
     var a = 22;
     var b = 4;
     // Smi & smi.
     Expect.equals(26, a + b);
     Expect.equals(18, a - b);
@@ skipping 368 matching lines @@
   static testMain() {
     for (int i = 0; i < 1500; i++) {
       runOne();
     }
   }
 }
 
 main() {
   ArithmeticTest.testMain();
 }