Plumbing changes to merge various element kind implementaions.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 5583abd1799f2841e6799326de6c03748077a018..bd1c568987bd1eaebc87cfa592650eb5ff9199c6 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -3576,12 +3576,6 @@ class Code: public HeapObject {
   inline CheckType check_type();
   inline void set_check_type(CheckType value);
 
-  // [external array type]: For kind KEYED_EXTERNAL_ARRAY_LOAD_IC and
-  // KEYED_EXTERNAL_ARRAY_STORE_IC, identifies the type of external
-  // array that the code stub is specialized for.
-  inline ExternalArrayType external_array_type();
-  inline void set_external_array_type(ExternalArrayType value);
-
   // [type-recording unary op type]: For all UNARY_OP_IC.
   inline byte unary_op_type();
   inline void set_unary_op_type(byte value);