Fix super ==: Test first for null before call inf super ==.

tests/co19/co19-runtime.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.
 
 [ $compiler == none && $runtime == vm ]
 # These tests need to be updated to the new Date core lib API, co19 issue 256:
 LibTest/core/Date/Date.fromMillisecondsSinceEpoch_A01_t01: Fail
 LibTest/core/Date/Date.fromMillisecondsSinceEpoch_A01_t02: Fail
 LibTest/core/Date/Date_A01_t04: Fail
 LibTest/core/Date/Date_A01_t05: Fail
@@ skipping 549 matching lines @@
 
 # initializer must be a compile time constant
 Language/10_Expressions/28_Identifier_Reference_A05_t09: Fail
 
 
 # invalid operator overloading
 Language/07_Classes/1_Instance_Methods/2_Operators_A02_t01: Fail
 Language/10_Expressions/15_Method_Invocation/2_Cascaded_Invocation_A01_t01: Fail
 Language/10_Expressions/22_Equality_A02_t03: Fail
 Language/10_Expressions/22_Equality_A03_t01: Fail
-Language/10_Expressions/22_Equality_A03_t02: Fail
 Language/10_Expressions/22_Equality_A03_t03: Fail
 
 
 # parameter name or type expected
 Language/07_Classes/6_Constructors/1_Generative_Constructors_A15_t07: Fail
 
 
 # using 'x' in this context is invalid
 Language/11_Statements/05_For_A01_t11: Fail
 
 
 [ $compiler == none && $runtime == vm ]
 LibTest/isolate/isolate_api/spawnFunction_A02_t01: Fail
 
 
 [ $compiler == none && $runtime == vm && $checked ]
 Language/03_Overview/1_Scoping_A02_t30: Fail
 
 
 [ $compiler == none && $runtime == vm && $mode == debug && $unchecked ]
 LibTest/isolate/isolate_api/spawnFunction_A02_t01: Crash
 
 [ $compiler == none && $arch == simarm ]
 *: Skip
 
 [ $compiler == none && $arch == arm ]
 *: Skip