Update V8 to r5017 as required by WebKit r62496

Change-Id: I1b4b7718d1d77ceef07f543e9150a2cb3a628f3a
diff --git a/src/x64/codegen-x64.h b/src/x64/codegen-x64.h
index cd03d2a..b9a3b70 100644
--- a/src/x64/codegen-x64.h
+++ b/src/x64/codegen-x64.h
@@ -393,6 +393,9 @@
   // target (which can not be done more than once).
   void GenerateReturnSequence(Result* return_value);
 
+  // Generate code for a fast smi loop.
+  void GenerateFastSmiLoop(ForStatement* node);
+
   // Returns the arguments allocation mode.
   ArgumentsAllocationMode ArgumentsMode();