Better support for 'polymorphic' JS and external arrays

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 0f9198c564dd19758cbdaa8336bfd7941ea585ee..68390454020d8a36f627370c19d5ef9738c2face 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -3270,12 +3270,10 @@ class Code: public HeapObject {
     BUILTIN,
     LOAD_IC,
     KEYED_LOAD_IC,
-    KEYED_EXTERNAL_ARRAY_LOAD_IC,
     CALL_IC,
     KEYED_CALL_IC,
     STORE_IC,
     KEYED_STORE_IC,
-    KEYED_EXTERNAL_ARRAY_STORE_IC,
     TYPE_RECORDING_BINARY_OP_IC,
     COMPARE_IC,
     // No more than 16 kinds. The value currently encoded in four bits in
@@ -3348,12 +3346,6 @@ class Code: public HeapObject {
     return kind() == TYPE_RECORDING_BINARY_OP_IC;
   }
   inline bool is_compare_ic_stub() { return kind() == COMPARE_IC; }
-  inline bool is_external_array_load_stub() {
-    return kind() == KEYED_EXTERNAL_ARRAY_LOAD_IC;
-  }
-  inline bool is_external_array_store_stub() {
-    return kind() == KEYED_EXTERNAL_ARRAY_STORE_IC;
-  }
 
   // [major_key]: For kind STUB or BINARY_OP_IC, the major key.
   inline int major_key();
@@ -3422,6 +3414,9 @@ class Code: public HeapObject {
   // Find the first map in an IC stub.
   Map* FindFirstMap();
 
+  // Return the number of maps
+  int GetMapCount();
+
   // Flags operations.
   static inline Flags ComputeFlags(
       Kind kind,