Unify internal and external typed arrays a bit

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HYDROGEN_INSTRUCTIONS_H_
 #define V8_HYDROGEN_INSTRUCTIONS_H_
 
 #include <cstring>
 #include <iosfwd>
 
@@ skipping 6112 matching lines @@
   static HObjectAccess ForJSArrayBufferByteLength() {
     return HObjectAccess::ForObservableJSObjectOffset(
         JSArrayBuffer::kByteLengthOffset, Representation::Tagged());
   }
 
   static HObjectAccess ForJSArrayBufferBitField() {
     return HObjectAccess::ForObservableJSObjectOffset(
         JSArrayBuffer::kBitFieldOffset, Representation::Integer32());
   }
 
+  static HObjectAccess ForJSArrayBufferBitFieldSlot() {
+    return HObjectAccess::ForObservableJSObjectOffset(
+        JSArrayBuffer::kBitFieldSlot, Representation::Smi());
+  }
+
   static HObjectAccess ForExternalArrayExternalPointer() {
     return HObjectAccess::ForObservableJSObjectOffset(
         ExternalArray::kExternalPointerOffset, Representation::External());
   }
 
   static HObjectAccess ForJSArrayBufferViewBuffer() {
     return HObjectAccess::ForObservableJSObjectOffset(
         JSArrayBufferView::kBufferOffset);
   }
 
@@ skipping 1703 matching lines @@
 };
 
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_