Add the native intrinsic TypedData_setRange to optimize the setRange call when the destination and …

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 20057)
+++ runtime/vm/object.h	(working copy)
@@ -4991,6 +4991,12 @@
                            intptr_t len,
                            Heap::Space space = Heap::kNew);
 
+  static void Copy(const TypedData& dst,
+                   intptr_t dst_offset_in_bytes,
+                   const TypedData& src,
+                   intptr_t src_offset_in_bytes,
+                   intptr_t length_in_bytes);
+
  protected:
   void SetLength(intptr_t value) const {
     raw_ptr()->length_ = Smi::New(value);
@@ -5079,6 +5085,12 @@
                                    intptr_t len,
                                    Heap::Space space = Heap::kNew);
 
+  static void Copy(const ExternalTypedData& dst,
+                   intptr_t dst_offset_in_bytes,
+                   const ExternalTypedData& src,
+                   intptr_t src_offset_in_bytes,
+                   intptr_t length_in_bytes);
+
  protected:
   void SetLength(intptr_t value) const {
     raw_ptr()->length_ = Smi::New(value);