Fix for issue #5227: do not declare type variables in the closure analyzer when they are not needed.

lib/compiler/implementation/closure.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.
 
 #library("closureToClassMapper");
 
 #import("elements/elements.dart");
 #import("leg.dart");
 #import("scanner/scannerlib.dart");
 #import("tree/tree.dart");
@@ skipping 356 matching lines @@
       if (type is TypeVariableType) {
         useLocal(type.element);
       } else if (type is InterfaceType) {
         InterfaceType ifcType = type;
         for (DartType argument in ifcType.arguments) {
           analyzeTypeVariables(argument);
         }
       }
     }
 
-    if (outermostFunctionElement.isInstanceMember()
-        || outermostFunctionElement.isGenerativeConstructor()) {
-      if (hasTypeVariable(type)) useLocal(closureData.thisElement);
-    } else if (outermostFunctionElement.isFactoryConstructor()) {
-      analyzeTypeVariables(type);
+    if (compiler.world.needsRti(outermostFunctionElement.enclosingElement)) {
+      if (outermostFunctionElement.isInstanceMember()
+          || outermostFunctionElement.isGenerativeConstructor()) {
+        if (hasTypeVariable(type)) useLocal(closureData.thisElement);
+      } else if (outermostFunctionElement.isFactoryConstructor()) {
+        analyzeTypeVariables(type);
+      }
     }
 
     node.visitChildren(this);
   }
 
   // If variables that are declared in the [node] scope are captured and need
   // to be boxed create a box-element and update the [capturingScopes] in the
   // current [closureData].
   // The boxed variables are updated in the [capturedVariableMapping].
   void attachCapturedScopeVariables(Node node) {
@@ skipping 148 matching lines @@
         declareLocal(closureData.thisElement);
       }
       // If we are inside a named closure we have to declare ourselve. For
       // simplicity we declare the local even if the closure does not have a
       // name.
       // It will simply not be used.
       if (insideClosure) {
         declareLocal(element);
       }
 
-      if (currentFunctionElement.isFactoryConstructor()) {
+      if (currentFunctionElement.isFactoryConstructor()
+          && compiler.world.needsRti(currentFunctionElement.enclosingElement)) {
         // Declare the type parameters in the scope. Generative
         // constructors just use 'this'.
         ClassElement cls = currentFunctionElement.enclosingElement;
         cls.typeVariables.forEach((TypeVariableType typeVariable) {
           declareLocal(typeVariable.element);
         });
       }
 
       // TODO(ahe): This is problematic. The backend should not repeat
       // the work of the resolver. It is the resolver's job to create
@@ skipping 33 matching lines @@
   }
 
   visitTryStatement(TryStatement node) {
     // TODO(ngeoffray): implement finer grain state.
     bool oldInTryStatement = inTryStatement;
     inTryStatement = true;
     node.visitChildren(this);
     inTryStatement = oldInTryStatement;
   }
 }