Fix cacthing exception object: a null exception is always caught.

tests/language/language.status

 # 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.
 
 # This directory contains tests that are intended to show the
 # current state of the language.
 
 # In order to maintain maximum test coverage for all builds,
 # please use the following procedure to mark a test
 # failed on architectures other than the one you are working on.
@@ skipping 209 matching lines @@
 #
 # Further explanation:
 # frog: frog compiler, run using the VM
 # frogsh: self-hosted frog compiler
 # frogium: Dart code compiled with frog VM running under DumpRenderTree
 # webdriver: Dart code compiled with frog VM running on an actual browser
 # (Chrome, IE, Firefox, Safari, etc). If a test is only failing on a particular
 # browser, you can be more specific about the failure by using $browser:
 # [ $component == webdriver && $browser == chrome ] for example.
 [ $component == frog || $component == frogsh || $component == frogium || $component == webdriver]
+ExceptionTest: Fail # Issue 1758
 Factory3Test: Fail # Issue 417
 Factory2NegativeTest: Fail
 CallThroughNullGetterTest: Fail # Throw ObjectNotClosure instead of NullPointerException.
 ExtendTypeParameterNegativeTest: Skip # Issue 886
 ExtendTypeParameter2NegativeTest: Skip # Issue 886
 FinalSyntaxTest/none: Fail
 GetSetSyntaxTest/00: Fail # Issue 1571
 GetSetSyntaxTest/01: Fail # Issue 1571
 GetSetSyntaxTest/02: Fail # Issue 1571
 GetSetSyntaxTest/03: Fail # Issue 1571
@@ skipping 216 matching lines @@
 [ $component == frog && $mode == debug ]
 ConstructorRedirect1NegativeTest: Skip # Undiagnosed infinite loop.
 ConstructorRedirect2NegativeTest: Skip # Undiagnosed infinite loop.
 
 [ $arch == simarm ]
 *: Skip
 
 [ $arch == arm ]
 *: Skip