Move all the closure related fields in RawFunction into a new class

vm/raw_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_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/token.h"
 #include "vm/snapshot.h"
 
 namespace dart {
 
 // Macrobatics to define the Object hierarchy of VM implementation classes.
 #define CLASS_LIST_NO_OBJECT(V)                                                \
   V(Class)                                                                     \
   V(UnresolvedClass)                                                           \
   V(AbstractType)                                                              \
     V(Type)                                                                    \
     V(TypeParameter)                                                           \
   V(AbstractTypeArguments)                                                     \
     V(TypeArguments)                                                           \
     V(InstantiatedTypeArguments)                                               \
   V(PatchClass)                                                                \
   V(Function)                                                                  \
+  V(ClosureData)                                                               \
   V(Field)                                                                     \
   V(LiteralToken)                                                              \
   V(TokenStream)                                                               \
   V(Script)                                                                    \
   V(Library)                                                                   \
   V(LibraryPrefix)                                                             \
   V(Code)                                                                      \
   V(Instructions)                                                              \
   V(PcDescriptors)                                                             \
   V(Stackmap)                                                                  \
@@ skipping 557 matching lines @@
   RAW_HEAP_OBJECT_IMPLEMENTATION(Function);
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->name_); }
   RawString* name_;
   RawObject* owner_;  // Class or  patch class where this function was defined.
   RawAbstractType* result_type_;
   RawArray* parameter_types_;
   RawArray* parameter_names_;
   RawCode* code_;  // Compiled code for the function.
   RawCode* unoptimized_code_;  // Unoptimized code, keep it after optimization.
-  RawContextScope* context_scope_;
-  RawFunction* parent_function_;  // Enclosing function of this local function.
-  RawClass* signature_class_;  // Only for closure or signature function.
-  RawCode* closure_allocation_stub_;  // Stub code for allocation of closures.
-  RawFunction* implicit_closure_function_;  // Implicit closure function.
+  RawObject* data_;  // Additional data specific to the function kind.
   RawObject** to() {
-    return reinterpret_cast<RawObject**>(&ptr()->implicit_closure_function_);
+    return reinterpret_cast<RawObject**>(&ptr()->data_);
   }
 
   intptr_t token_pos_;
   intptr_t end_token_pos_;
   intptr_t num_fixed_parameters_;
   intptr_t num_optional_positional_parameters_;
   intptr_t num_optional_named_parameters_;
   intptr_t usage_counter_;  // Incremented while function is running.
   uint16_t deoptimization_counter_;
   uint16_t kind_tag_;
 };
 
 
+class RawClosureData : public RawObject {
+ private:
+  RAW_HEAP_OBJECT_IMPLEMENTATION(ClosureData);
+
+  RawObject** from() {
+    return reinterpret_cast<RawObject**>(&ptr()->context_scope_);
+  }
+  RawContextScope* context_scope_;
+  RawFunction* parent_function_;  // Enclosing function of this local function.
+  RawClass* signature_class_;
+  RawCode* closure_allocation_stub_;  // Stub code for allocation of closures.
+  RawObject** to() {
+    return reinterpret_cast<RawObject**>(&ptr()->closure_allocation_stub_);
+  }
+};
+
+
 class RawField : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(Field);
 
   RawObject** from() { return reinterpret_cast<RawObject**>(&ptr()->name_); }
   RawString* name_;
   RawClass* owner_;
   RawAbstractType* type_;
   RawInstance* value_;  // Offset for instance and value for static fields.
   RawObject** to() { return reinterpret_cast<RawObject**>(&ptr()->value_); }
 
@@ skipping 957 matching lines @@
          kExternalUint64ArrayCid == kByteArrayCid + 18 &&
          kExternalFloat32ArrayCid == kByteArrayCid + 19 &&
          kExternalFloat64ArrayCid == kByteArrayCid + 20 &&
          kStacktraceCid == kByteArrayCid + 21);
   return (index >= kByteArrayCid && index <= kExternalFloat64ArrayCid);
 }
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_