Don't allow invoking a constructor as 'const' if it wasn't declared 'const'.

tests/language/language.status

 # 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.
 
 # 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 76 matching lines @@
 BlackListedTest/09: Fail # Bug 5469684
 BlackListedTest/10: Fail # Bug 5469684
 BlackListedTest/11: Fail # Bug 5469684
 BlackListedTest/12: Fail # Bug 5469684
 BlackListedTest/13: Crash # Bug 5469684
 BlackListedTest/14: Crash # Bug 5469684
 CTConstTest: Fail            # Bug 4510015.
 CallThroughNullGetterTest: Fail # Throw ObjectNotClosure instead of NullPointerException.
 CharEscapeTest: Fail
 ClassOverrideNegativeTest: Fail  # Bug 4205768.
-ConstConstructor1NegativeTest: FAIL      # Bug 5142545
-ConstConstructor2NegativeTest: FAIL      # Bug 5142545
 DefaultFactoryLibraryTest: Fail          # Issue 514
 ConstObjectsAreImmutableTest: Fail  # Bug 5202940
 Constructor2NegativeTest: Fail  # Bug 4208594.
 Constructor2Test: Fail       # Issue 255
 Constructor3Test: Fail       # Issue 257
 Constructor4Test: Fail       # Issue 286
 Constructor5Test: Fail       # Issue 8440015 + 'super' initializer does not parse
 Constructor6Test: Fail       # Issue 8440015 + 'super' initializer does not parse
 DivByZeroTest: Fail          # Bug 5184183
 DynamicTest: Crash            # Bug 5527899.
@@ skipping 234 matching lines @@
 StaticField2RunNegativeTest: Fail
 
 [ $arch == x64 ]
 *: Skip
 
 [ $arch == simarm ]
 *: Skip
 
 [ $arch == arm ]
 *: Skip