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

tests/language/type_variable_scope2_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.
 
 // Test that malformed type arguments are reported in checked mode.
 
 isCheckedMode() {
   try {
     var i = 1;
     String s = i;
     return false;
-  } catch(var e) {
+  } catch (e) {
     return true;
   }
 }
 
 class Foo<T> {
   // T is not in scope for a static method.
   static Foo<T> m() {
     return new Foo();
   }
 }
 
 main() {
   bool got_type_error = false;
   try {
     Expect.isTrue(Foo.m() is Foo);
-  } catch (TypeError error) {
+  } on TypeError catch (error) {
     got_type_error = true;
   }
   // Type error in checked mode only.
   Expect.isTrue(got_type_error == isCheckedMode());
 }