Use .callMethod instead of LocalFunctionElement as key in inference

pkg/compiler/lib/src/ssa/builder.dart

 // Copyright (c) 2012, 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.
 
 import 'dart:collection';
 
 import 'package:js_runtime/shared/embedded_names.dart';
 
 import '../closure.dart';
 import '../common.dart';
@@ skipping 688 matching lines @@
     return graph.addConstant(getConstantForNode(node), closedWorld);
   }
 
   /**
    * Documentation wanted -- johnniwinther
    *
    * Invariant: [functionElement] must be an implementation element.
    */
   HGraph buildMethod(MethodElement functionElement) {
     assert(functionElement.isImplementation, failedAt(functionElement));
-    graph.calledInLoop =
-        closedWorld.isCalledInLoop(functionElement.declaration);
+    MethodElement declaration = functionElement.declaration;
+    graph.calledInLoop = closedWorld.isCalledInLoop(declaration);
     ast.FunctionExpression function = resolvedAst.node;
     assert(function != null);
     assert(elements.getFunctionDefinition(function) != null);
     openFunction(functionElement, function);
     String name = functionElement.name;
     if (nativeData.isJsInteropMember(functionElement)) {
       push(invokeJsInteropFunction(functionElement, parameters.values.toList(),
           sourceInformationBuilder.buildGeneric(function)));
       var value = pop();
       closeAndGotoExit(new HReturn(
@@ skipping 6123 matching lines @@
       this.oldReturnLocal,
       this.oldReturnType,
       this.oldResolvedAst,
       this.oldStack,
       this.oldLocalsHandler,
       this.inTryStatement,
       this.allFunctionsCalledOnce,
       this.oldElementInferenceResults)
       : super(function);
 }