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

tests/lib/math/math2_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.
 
 // We temporarily test both the new math library and the old Math
 // class. This can easily be simplified once we get rid of the Math
 // class entirely.
 #library('math_test');
 #import('dart:math', prefix: 'math');
 
@@ skipping 140 matching lines @@
   static void testPow() {
     checkVeryClose(16.0, math.pow(4.0, 2.0));
     checkVeryClose(math.SQRT2, math.pow(2.0, 0.5));
     checkVeryClose(math.SQRT1_2, math.pow(0.5, 0.5));
   }
 
   static bool parseIntThrowsFormatException(str) {
     try {
       math.parseInt(str);
       return false;
-    } catch (FormatException e) {
+    } on FormatException catch (e) {
       return true;
     }
   }
 
   static void testParseInt() {
     Expect.equals(499, math.parseInt("499"));
     Expect.equals(499, math.parseInt("+499"));
     Expect.equals(-499, math.parseInt("-499"));
     Expect.equals(499, math.parseInt("   499   "));
     Expect.equals(499, math.parseInt("   +499   "));
@@ skipping 82 matching lines @@
     testLog();
     testExp();
     testPow();
     testParseInt();
   }
 }
 
 main() {
   MathLibraryTest.testMain();
 }