Fix 56 hints in pkg/compiler

pkg/compiler/lib/src/inferrer/node_tracer.dart

 // Copyright (c) 2013, 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.
 
 part of type_graph_inferrer;
 
 // A set of selectors we know do not escape the elements inside the
 // list.
 Set<String> doesNotEscapeListSet = new Set<String>.from(
   const <String>[
@@ skipping 347 matching lines @@
     // TODO(herhut): Handle creation of closures from instances of Function.
     if (element.isInstanceMember &&
         element.name == Compiler.CALL_OPERATOR_NAME) {
       return true;
     }
     Element outermost = element.outermostEnclosingMemberOrTopLevel;
     return outermost.declaration != element.declaration;
   }
 
   void visitMemberTypeInformation(MemberTypeInformation info) {
-    Element element = info.element;
     if (info.isClosurized) {
       bailout('Returned from a closurized method');
     }
     if (isClosure(info.element)) {
       bailout('Returned from a closure');
     }
     if (!inferrer.compiler.backend
         .canBeUsedForGlobalOptimizations(info.element)) {
       bailout('Escape to code that has special backend treatment');
     }
@@ skipping 11 matching lines @@
     }
     if (isParameterOfListAddingMethod(info.element) ||
         isParameterOfMapAddingMethod(info.element)) {
       // These elements are being handled in
       // [visitDynamicCallSiteTypeInformation].
       return;
     }
     addNewEscapeInformation(info);
   }
 }