Introduce a code stub version of Array.prototype.push

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index cc4b279976a54d573d76eba861235e48d8a19250..d8fc2db17a671e8119fe46a06c874e1d2cc402bd 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -3074,6 +3074,11 @@ class DescriptorArray: public FixedArray {
     return ToKeyIndex(number_of_descriptors);
   }
 
+  static int ToDetailsIndex(int descriptor_number) {
+    return kFirstIndex + (descriptor_number * kDescriptorSize) +
+           kDescriptorDetails;
+  }
+
  private:
   // An entry in a DescriptorArray, represented as an (array, index) pair.
   class Entry {
@@ -3096,12 +3101,6 @@ class DescriptorArray: public FixedArray {
            kDescriptorKey;
   }
 
-  static int ToDetailsIndex(int descriptor_number) {
-    return kFirstIndex +
-           (descriptor_number * kDescriptorSize) +
-           kDescriptorDetails;
-  }
-
   static int ToValueIndex(int descriptor_number) {
     return kFirstIndex +
            (descriptor_number * kDescriptorSize) +