Add the allocator intrinsics for dart:typeddata implementation.

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 4954 matching lines @@
   static intptr_t InstanceSize(intptr_t lengthInBytes) {
     ASSERT(0 <= lengthInBytes && lengthInBytes <= kSmiMax);
     return RoundedAllocationSize(sizeof(RawTypedData) + lengthInBytes);
   }
 
   static intptr_t ElementSizeInBytes(intptr_t class_id) {
     ASSERT(RawObject::IsTypedDataClassId(class_id));
     return element_size[class_id - kTypedDataInt8ArrayCid];
   }
 
+  static intptr_t MaxElements(intptr_t class_id) {
+    ASSERT(RawObject::IsTypedDataClassId(class_id));
+    return (kSmiMax / ElementSizeInBytes(class_id));
+  }
+
   static RawTypedData* New(intptr_t class_id,
                            intptr_t len,
                            Heap::Space space = Heap::kNew);
 
  protected:
   void SetLength(intptr_t value) const {
     raw_ptr()->length_ = Smi::New(value);
   }
 
  private:
@@ skipping 58 matching lines @@
 
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawExternalTypedData));
   }
 
   static intptr_t ElementSizeInBytes(intptr_t class_id) {
     ASSERT(RawObject::IsExternalTypedDataClassId(class_id));
     return TypedData::element_size[class_id - kExternalTypedDataInt8ArrayCid];
   }
 
+  static intptr_t MaxElements(intptr_t class_id) {
+    ASSERT(RawObject::IsExternalTypedDataClassId(class_id));
+    return (kSmiMax / ElementSizeInBytes(class_id));
+  }
+
   static RawExternalTypedData* New(intptr_t class_id,
                                    uint8_t* data,
                                    intptr_t len,
                                    Heap::Space space = Heap::kNew);
 
  protected:
   void SetLength(intptr_t value) const {
     raw_ptr()->length_ = Smi::New(value);
   }
 
@@ skipping 1751 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_