[collections] Shuffle OrderedHashTable fields around for future optimization

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 783ed61fd37912461ff002431d19fa703f049c6b..189649836baaa79412a24d9a770b9ef9e13002ae 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2874,10 +2874,12 @@ class FixedArray: public FixedArrayBase {
   void CopyTo(int pos, FixedArray* dest, int dest_pos, int len);
 
   // Garbage collection support.
-  static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; }
+  static constexpr int SizeFor(int length) {
+    return kHeaderSize + length * kPointerSize;
+  }
 
   // Code Generation support.
-  static int OffsetOfElementAt(int index) { return SizeFor(index); }
+  static constexpr int OffsetOfElementAt(int index) { return SizeFor(index); }
 
   // Garbage collection support.
   inline Object** RawFieldOfElementAt(int index);
@@ -4278,22 +4280,23 @@ class OrderedHashTable: public FixedArray {
   static const int kNotFound = -1;
   static const int kMinCapacity = 4;
 
-  static const int kNumberOfBucketsIndex = 0;
-  static const int kNumberOfElementsIndex = kNumberOfBucketsIndex + 1;
-  static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1;
-  static const int kHashTableStartIndex = kNumberOfDeletedElementsIndex + 1;
+  static const int kNumberOfElementsIndex = 0;
+  // The next table is stored at the same index as the nof elements.
   static const int kNextTableIndex = kNumberOfElementsIndex;
-
-  static const int kNumberOfBucketsOffset =
-      kHeaderSize + kNumberOfBucketsIndex * kPointerSize;
-  static const int kNumberOfElementsOffset =
-      kHeaderSize + kNumberOfElementsIndex * kPointerSize;
-  static const int kNumberOfDeletedElementsOffset =
-      kHeaderSize + kNumberOfDeletedElementsIndex * kPointerSize;
-  static const int kHashTableStartOffset =
-      kHeaderSize + kHashTableStartIndex * kPointerSize;
-  static const int kNextTableOffset =
-      kHeaderSize + kNextTableIndex * kPointerSize;
+  static const int kNumberOfDeletedElementsIndex = kNumberOfElementsIndex + 1;
+  static const int kNumberOfBucketsIndex = kNumberOfDeletedElementsIndex + 1;
+  static const int kHashTableStartIndex = kNumberOfBucketsIndex + 1;
+
+  static constexpr const int kNumberOfElementsOffset =
+      FixedArray::OffsetOfElementAt(kNumberOfElementsIndex);
+  static constexpr const int kNextTableOffset =
+      FixedArray::OffsetOfElementAt(kNextTableIndex);
+  static constexpr const int kNumberOfDeletedElementsOffset =
+      FixedArray::OffsetOfElementAt(kNumberOfDeletedElementsIndex);
+  static constexpr const int kNumberOfBucketsOffset =
+      FixedArray::OffsetOfElementAt(kNumberOfBucketsIndex);
+  static constexpr const int kHashTableStartOffset =
+      FixedArray::OffsetOfElementAt(kHashTableStartIndex);
 
   static const int kEntrySize = entrysize + 1;
   static const int kChainOffset = entrysize;