Plumbing changes to merge various element kind implementaions.

src/x64/lithium-x64.h

Index: src/x64/lithium-x64.h
diff --git a/src/x64/lithium-x64.h b/src/x64/lithium-x64.h
index 507667ea86b522dfc9a7e30b88588ef5780dcf99..b2464eab9db6b26782ab5234f2d02caa2223eafe 100644
--- a/src/x64/lithium-x64.h
+++ b/src/x64/lithium-x64.h
@@ -1297,8 +1297,8 @@ class LLoadKeyedSpecializedArrayElement: public LTemplateInstruction<1, 2, 0> {
 
   LOperand* external_pointer() { return inputs_[0]; }
   LOperand* key() { return inputs_[1]; }
-  ExternalArrayType array_type() const {
-    return hydrogen()->array_type();
+  JSObject::ElementsKind elements_kind() const {
+    return hydrogen()->elements_kind();
   }
 };
 
@@ -1750,8 +1750,8 @@ class LStoreKeyedSpecializedArrayElement: public LTemplateInstruction<0, 3, 0> {
   LOperand* external_pointer() { return inputs_[0]; }
   LOperand* key() { return inputs_[1]; }
   LOperand* value() { return inputs_[2]; }
-  ExternalArrayType array_type() const {
-    return hydrogen()->array_type();
+  JSObject::ElementsKind elements_kind() const {
+    return hydrogen()->elements_kind();
   }
 };