Preserve type variables in closure conversion.

pkg/kernel/lib/clone.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.clone;
 
 import 'ast.dart';
 import 'type_algebra.dart';
 
 /// Visitor that return a clone of a tree, maintaining references to cloned
 /// objects.
@@ skipping 217 matching lines @@
   }
 
   visitVectorCreation(VectorCreation node) {
     return new VectorCreation(node.length);
   }
 
   visitClosureCreation(ClosureCreation node) {
     return new ClosureCreation.byReference(
         node.topLevelFunctionReference,
         cloneOptional(node.contextVector),
-        visitOptionalType(node.functionType));
+        visitOptionalType(node.functionType),
+        node.typeArgs.map(visitType).toList());
   }
 
   visitVectorSet(VectorSet node) {
     return new VectorSet(
         clone(node.vectorExpression), node.index, clone(node.value));
   }
 
   visitVectorGet(VectorGet node) {
     return new VectorGet(clone(node.vectorExpression), node.index);
   }
@@ skipping 183 matching lines @@
   visitArguments(Arguments node) {
     return new Arguments(node.positional.map(clone).toList(),
         types: node.types.map(visitType).toList(),
         named: node.named.map(clone).toList());
   }
 
   visitNamedExpression(NamedExpression node) {
     return new NamedExpression(node.name, clone(node.value));
   }
 }