Track field types.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index ed66dc6423c8764ffb9c0778f8bb2192a9da259e..2c89a148f1bdf5ec5136e644a9e0b1232801a3ed 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -286,6 +286,7 @@ bool Object::IsExternalTwoByteString() {
          String::cast(this)->IsTwoByteRepresentation();
 }
 
+
 bool Object::HasValidElements() {
   // Dictionary is covered under FixedArray.
   return IsFixedArray() || IsFixedDoubleArray() || IsExternalArray() ||
@@ -2723,14 +2724,6 @@ void DescriptorArray::SetRepresentation(int descriptor_index,
 }
 
 
-void DescriptorArray::InitializeRepresentations(Representation representation) {
-  int length = number_of_descriptors();
-  for (int i = 0; i < length; i++) {
-    SetRepresentation(i, representation);
-  }
-}
-
-
 Object** DescriptorArray::GetValueSlot(int descriptor_number) {
   ASSERT(descriptor_number < number_of_descriptors());
   return RawFieldOfElementAt(ToValueIndex(descriptor_number));
@@ -2743,6 +2736,11 @@ Object* DescriptorArray::GetValue(int descriptor_number) {
 }
 
 
+void DescriptorArray::SetValue(int descriptor_index, Object* value) {
+  set(ToValueIndex(descriptor_index), value);
+}
+
+
 PropertyDetails DescriptorArray::GetDetails(int descriptor_number) {
   ASSERT(descriptor_number < number_of_descriptors());
   Object* details = get(ToDetailsIndex(descriptor_number));
@@ -2761,6 +2759,12 @@ int DescriptorArray::GetFieldIndex(int descriptor_number) {
 }
 
 
+HeapType* DescriptorArray::GetFieldType(int descriptor_number) {
+  ASSERT(GetDetails(descriptor_number).type() == FIELD);
+  return HeapType::cast(GetValue(descriptor_number));
+}
+
+
 Object* DescriptorArray::GetConstant(int descriptor_number) {
   return GetValue(descriptor_number);
 }