Fix more strong mode errors in analyzer

pkg/analyzer/lib/src/summary/resynthesize.dart

 // Copyright (c) 2015, 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 summary_resynthesizer;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 705 matching lines @@
     components.add(name);
     ElementLocationImpl location = new ElementLocationImpl.con3(components);
     return new _DeferredConstructorElement._(definingType, name, location);
   }
 
   _DeferredConstructorElement._(
       this._definingType, this.name, ElementLocation location)
       : super(null, location);
 
   @override
-  Element get actualElement => enclosingElement.getNamedConstructor(name);
+  ConstructorElement get actualElement =>
+      enclosingElement.getNamedConstructor(name);
 
   @override
   AnalysisContext get context => _definingType.element.context;
 
   @override
   String get displayName => name;
 
   @override
   ClassElement get enclosingElement {
     return _definingType.element;
@@ skipping 581 matching lines @@
           FunctionTypedElement element = this.element;
           for (int index in implicitFunctionTypeIndices) {
             element = element.parameters[index].type.element;
           }
           return element;
         };
       } else {
         // For a type that refers to a generic executable, the type arguments are
         // not supposed to include the arguments to the executable itself.
         numTypeArguments = enclosing == null ? 0 : enclosing.numTypeParameters;
-        computer = () => this.element;
+        computer = () => this.element as FunctionTypedElement;
       }
       // TODO(paulberry): Is it a bug that we have to pass `false` for
       // isInstantiated?
       return new DeferredFunctionTypeImpl(computer, null,
           _buildTypeArguments(numTypeArguments, getTypeArgument), false);
     } else {
       return null;
     }
   }
 
@@ skipping 1252 matching lines @@
   static String _getElementIdentifier(String name, ReferenceKind kind) {
     if (kind == ReferenceKind.topLevelPropertyAccessor ||
         kind == ReferenceKind.propertyAccessor) {
       if (!name.endsWith('=')) {
         return name + '?';
       }
     }
     return name;
   }
 }