Fix for issue 6623 - Canonicalize implicit static closure objects.

runtime/vm/object.h

 // 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.
 
 #ifndef VM_OBJECT_H_
 #define VM_OBJECT_H_
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ skipping 1129 matching lines @@
   RawContextScope* context_scope() const;
   void set_context_scope(const ContextScope& value) const;
 
   // Enclosing function of this local function.
   RawFunction* parent_function() const;
 
   // Signature class of this closure function or signature function.
   RawClass* signature_class() const;
   void set_signature_class(const Class& value) const;
 
+  RawInstance* implicit_static_closure() const;
+  void set_implicit_static_closure(const Instance& closure) const;
+
   RawCode* closure_allocation_stub() const;
   void set_closure_allocation_stub(const Code& value) const;
 
   // Return the closure function implicitly created for this function.
   // If none exists yet, create one and remember it.
   RawFunction* ImplicitClosureFunction() const;
 
   // Redirection information for a redirecting factory.
   bool IsRedirectingFactory() const;
   RawType* RedirectionType() const;
@@ skipping 353 matching lines @@
   void set_context_scope(const ContextScope& value) const;
 
   // Enclosing function of this local function.
   RawFunction* parent_function() const { return raw_ptr()->parent_function_; }
   void set_parent_function(const Function& value) const;
 
   // Signature class of this closure function or signature function.
   RawClass* signature_class() const { return raw_ptr()->signature_class_; }
   void set_signature_class(const Class& value) const;
 
+  RawInstance* implicit_static_closure() const {
+    return raw_ptr()->closure_;
+  }
+  void set_implicit_static_closure(const Instance& closure) const;
+
   RawCode* closure_allocation_stub() const {
     return raw_ptr()->closure_allocation_stub_;
   }
   void set_closure_allocation_stub(const Code& value) const;
 
   static RawClosureData* New();
 
   HEAP_OBJECT_IMPLEMENTATION(ClosureData, Object);
   friend class Class;
   friend class Function;
@@ skipping 4341 matching lines @@
     if (this->CharAt(i) != str.CharAt(begin_index + i)) {
       return false;
     }
   }
   return true;
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_