Merge array allocation and List._copyFromObjectArray to provide fast path for large arrays.

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 6224 matching lines @@
   // Return an Array object that contains all the elements currently present
   // in the specified Growable Object Array. This is done by first truncating
   // the Growable Object Array's backing array to the currently used size and
   // returning the truncated backing array.
   // The remaining unused part of the backing array is marked as an Array
   // object or a regular Object so that it can be traversed during garbage
   // collection. The backing array of the original Growable Object Array is
   // set to an empty array.
   static RawArray* MakeArray(const GrowableObjectArray& growable_array);
 
+  RawArray* Slice(intptr_t start,
+                  intptr_t count,
+                  bool with_type_argument) const;
+
  protected:
   static RawArray* New(intptr_t class_id,
                        intptr_t len,
                        Heap::Space space = Heap::kNew);
 
  private:
   RawObject** ObjectAddr(intptr_t index) const {
     // TODO(iposva): Determine if we should throw an exception here.
     ASSERT((index >= 0) && (index < Length()));
     return &raw_ptr()->data()[index];
@@ skipping 1161 matching lines @@
 
 
 RawObject* MegamorphicCache::GetTargetFunction(const Array& array,
                                                intptr_t index) {
   return array.At((index * kEntryLength) + kTargetFunctionIndex);
 }
 
 }  // namespace dart
 
 #endif  // VM_OBJECT_H_