Workaround for ConstantVisitor dependency issues.

pkg/analyzer/lib/src/generated/engine.dart

 // Copyright (c) 2014, 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 code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine;
 
 import 'dart:collection';
@@ skipping 8794 matching lines @@
       ErrorReporter errorReporter = new ErrorReporter(errorListener, source);
       TypeProvider typeProvider = context.typeProvider;
       //
       // Validate the directives
       //
       validateDirectives(context, source, _unit, errorListener);
       //
       // Use the ConstantVerifier to verify the use of constants. This needs to happen before using
       // the ErrorVerifier because some error codes need the computed constant values.
       //
-      ConstantVerifier constantVerifier = new ConstantVerifier(errorReporter, libraryElement, typeProvider);
-      _unit.accept(constantVerifier);
+      // TODO(paulberry): as a temporary workaround for issue 21572,
+      // ConstantVerifier is being run right after ConstantValueComputer, so we
+      // don't need to run it here.  Once issue 21572 is fixed, re-enable the
+      // call to ConstantVerifier.
+      // ConstantVerifier constantVerifier = new ConstantVerifier(errorReporter, libraryElement, typeProvider);
+      // _unit.accept(constantVerifier);
       //
       // Use the ErrorVerifier to compute the rest of the errors.
       //
       ErrorVerifier errorVerifier = new ErrorVerifier(errorReporter, libraryElement, typeProvider, new InheritanceManager(libraryElement));
       _unit.accept(errorVerifier);
       _errors = errorListener.getErrorsForSource(source);
     } finally {
       timeCounter.stop();
     }
   }
@@ skipping 3798 matching lines @@
     ResolverVisitor resolverVisitor = new ResolverVisitor.con2(_libraryElement, source, typeProvider, inheritanceManager, errorListener);
     unit.accept(resolverVisitor);
     //
     // Perform additional error checking.
     //
     TimeCounter_TimeCounterHandle counterHandleErrors = PerformanceStatistics.errors.start();
     try {
       ErrorReporter errorReporter = new ErrorReporter(errorListener, source);
       ErrorVerifier errorVerifier = new ErrorVerifier(errorReporter, _libraryElement, typeProvider, inheritanceManager);
       unit.accept(errorVerifier);
-      ConstantVerifier constantVerifier = new ConstantVerifier(errorReporter, _libraryElement, typeProvider);
-      unit.accept(constantVerifier);
+      // TODO(paulberry): as a temporary workaround for issue 21572,
+      // ConstantVerifier is being run right after ConstantValueComputer, so we
+      // don't need to run it here.  Once issue 21572 is fixed, re-enable the
+      // call to ConstantVerifier.
+      // ConstantVerifier constantVerifier = new ConstantVerifier(errorReporter, _libraryElement, typeProvider);
+      // unit.accept(constantVerifier);
     } finally {
       counterHandleErrors.stop();
     }
     //
     // Capture the results.
     //
     _resolvedUnit = unit;
   }
 
   /**
@@ skipping 914 matching lines @@
     _index++;
     if (_index >= _manager._workQueues[_queueIndex].length) {
       _index = 0;
       _queueIndex++;
       while (_queueIndex < _manager._workQueues.length && _manager._workQueues[_queueIndex].isEmpty) {
         _queueIndex++;
       }
     }
   }
 }