Remove ContextClass that is not needed since we're using Vectors

pkg/kernel/lib/transformations/closure/converter.dart

 // Copyright (c) 2016, 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 kernel.transformations.closure.converter;
 
 import '../../ast.dart'
     show
         Arguments,
         Block,
@@ skipping 56 matching lines @@
 import 'clone_without_body.dart' show CloneWithoutBody;
 
 import 'context.dart' show Context, NoContext;
 
 import 'info.dart' show ClosureInfo;
 
 import 'rewriter.dart' show AstRewriter, BlockRewriter, InitializerRewriter;
 
 class ClosureConverter extends Transformer {
   final CoreTypes coreTypes;
-  final Class contextClass;
   final Set<VariableDeclaration> capturedVariables;
   final Map<FunctionNode, Set<TypeParameter>> capturedTypeVariables;
   final Map<FunctionNode, VariableDeclaration> thisAccess;
   final Map<FunctionNode, String> localNames;
 
   /// Records place-holders for cloning contexts. See [visitForStatement].
   final Set<InvalidExpression> contextClonePlaceHolders =
       new Set<InvalidExpression>();
 
   /// Maps the names of all instance methods that may be torn off (aka
@@ skipping 41 matching lines @@
   ///    }
   ///    class Closure#0<T_> implements Function {
   ///      call(x) => x is T_;
   ///    }
   ///
   /// In this example, `typeSubstitution[T].parameter == T_` when transforming
   /// the closure in `f`.
   Map<TypeParameter, DartType> typeSubstitution =
       const <TypeParameter, DartType>{};
 
-  ClosureConverter(this.coreTypes, ClosureInfo info, this.contextClass)
+  ClosureConverter(this.coreTypes, ClosureInfo info)
       : this.capturedVariables = info.variables,
         this.capturedTypeVariables = info.typeVariables,
         this.thisAccess = info.thisAccess,
         this.localNames = info.localNames,
         this.tearOffGetterNames = info.tearOffGetterNames;
 
   bool get isOuterMostContext {
     return currentFunction == null || currentMemberFunction == currentFunction;
   }
 
@@ skipping 10 matching lines @@
     try {
       return f();
     } finally {
       rewriter = old;
       context = savedContext;
     }
   }
 
   TreeNode visitLibrary(Library node) {
     assert(newLibraryMembers.isEmpty);
-    if (node == contextClass.enclosingLibrary) return node;
 
     currentLibrary = node;
     node = super.visitLibrary(node);
     for (TreeNode member in newLibraryMembers) {
       if (member is Class) {
         node.addClass(member);
       } else {
         node.addMember(member);
       }
     }
@@ skipping 697 matching lines @@
         newClassMembers.add(tearOffMethod);
 
         resetContext();
       });
     } finally {
       currentMember = oldCurrentMember;
       currentMemberFunction = oldCurrentMemberFunction;
     }
   }
 }