Make type system changes backwards compatible

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.
 
 library engine;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:math' as math;
 
@@ skipping 8472 matching lines @@
   @override
   accept(AnalysisTaskVisitor visitor) =>
       visitor.visitGenerateDartErrorsTask(this);
 
   @override
   void internalPerform() {
     PerformanceStatistics.errors.makeCurrentWhile(() {
       RecordingErrorListener errorListener = new RecordingErrorListener();
       ErrorReporter errorReporter = new ErrorReporter(errorListener, source);
       TypeProvider typeProvider = context.typeProvider;
-      TypeSystem typeSystem = context.typeSystem;
       //
       // 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.
       //
       // 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,
-          typeSystem,
           new InheritanceManager(libraryElement),
           context.analysisOptions.enableSuperMixins);
       _unit.accept(errorVerifier);
       _errors = errorListener.getErrorsForSource(source);
     });
   }
 
   /**
    * Check each directive in the given compilation unit to see if the referenced source exists and
    * report an error if it does not.
@@ skipping 2416 matching lines @@
     }
     return "resolve unit ${librarySource.fullName}";
   }
 
   @override
   accept(AnalysisTaskVisitor visitor) => visitor.visitResolveDartUnitTask(this);
 
   @override
   void internalPerform() {
     TypeProvider typeProvider = _libraryElement.context.typeProvider;
-    TypeSystem typeSystem = _libraryElement.context.typeSystem;
     CompilationUnit unit = context.computeResolvableCompilationUnit(source);
     if (unit == null) {
       throw new AnalysisException(
           "Internal error: computeResolvableCompilationUnit returned a value without a parsed Dart unit");
     }
     //
     // Resolve names in declarations.
     //
     new DeclarationResolver().resolve(unit, _find(_libraryElement, source));
     //
     // Resolve the type names.
     //
     RecordingErrorListener errorListener = new RecordingErrorListener();
     TypeResolverVisitor typeResolverVisitor = new TypeResolverVisitor(
         _libraryElement, source, typeProvider, errorListener);
     unit.accept(typeResolverVisitor);
     //
     // Resolve the rest of the structure
     //
     InheritanceManager inheritanceManager =
         new InheritanceManager(_libraryElement);
     ResolverVisitor resolverVisitor = new ResolverVisitor(
-        _libraryElement, source, typeProvider, typeSystem, errorListener,
+        _libraryElement, source, typeProvider, errorListener,
         inheritanceManager: inheritanceManager);
     unit.accept(resolverVisitor);
     //
     // Perform additional error checking.
     //
     PerformanceStatistics.errors.makeCurrentWhile(() {
       ErrorReporter errorReporter = new ErrorReporter(errorListener, source);
       ErrorVerifier errorVerifier = new ErrorVerifier(
           errorReporter,
           _libraryElement,
           typeProvider,
-          typeSystem,
           inheritanceManager,
           context.analysisOptions.enableSuperMixins);
       unit.accept(errorVerifier);
       // 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);
     });
@@ skipping 1075 matching lines @@
     PendingFuture pendingFuture =
         new PendingFuture<T>(_context, source, computeValue);
     if (!pendingFuture.evaluate(sourceEntry)) {
       _context._pendingFutureSources
           .putIfAbsent(source, () => <PendingFuture>[])
           .add(pendingFuture);
     }
     return pendingFuture.future;
   }
 }