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

tests/compiler/dart2js_native/native_exceptions1_frog_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.
 
 // Test that hidden native exception classes can be marked as existing.
 //
 // To infer which native hidden types exist, we need
 //   (1) return types of native methods and getters
 //   (2) argument types of callbacks
 //   (3) exceptions thrown by the operation.
@@ skipping 54 matching lines @@
   var a = things[inscrutable(0)];
   var b = things[inscrutable(1)];
 
   Expect.equals(25, a.op(50));
   Expect.equals(123, b.op('hello'));
   Expect.equals(666, b.code);
 
   bool threw = false;
   try {
     var x = a.op(51);
-  } catch (var e) {
+  } catch (e) {
     threw = true;
     Expect.equals(100, e.code);
     Expect.isTrue(e is E);
   }
   Expect.isTrue(threw);
 
   // Again, but with statically typed receivers.
   A aa = a;
   B bb = b;
 
   Expect.equals(25, aa.op(50));
   Expect.equals(123, bb.op('hello'));
   Expect.equals(666, bb.code);
 
   threw = false;
   try {
     var x = aa.op(51);
-  } catch (E e) {
+  } on E catch (e) {
     threw = true;
     Expect.equals(100, e.code);
     Expect.isTrue(e is E);
   }
   Expect.isTrue(threw);
 }