Merge V8 5.3.332.45.  DO NOT MERGE

Test: Manual

FPIIM-449

Change-Id: Id3254828b068abdea3cb10442e0172a8c9a98e03
(cherry picked from commit 13e2dadd00298019ed862f2b2fc5068bba730bcf)
diff --git a/src/compiler/int64-lowering.h b/src/compiler/int64-lowering.h
index 054c421..4ec4e82 100644
--- a/src/compiler/int64-lowering.h
+++ b/src/compiler/int64-lowering.h
@@ -26,6 +26,9 @@
   static int GetParameterCountAfterLowering(
       Signature<MachineRepresentation>* signature);
 
+  static const int kLowerWordOffset;
+  static const int kHigherWordOffset;
+
  private:
   enum class State : uint8_t { kUnvisited, kOnStack, kVisited };
 
@@ -54,6 +57,7 @@
   bool HasReplacementHigh(Node* node);
   Node* GetReplacementHigh(Node* node);
   void PreparePhiReplacement(Node* phi);
+  void GetIndexNodes(Node* index, Node*& index_low, Node*& index_high);
 
   struct NodeState {
     Node* node;