Update V8 to r5295 as required by WebKit r65615

Change-Id: I1d72d4990703e88b7798919c7a53e12ebf76958a
diff --git a/src/x64/macro-assembler-x64.h b/src/x64/macro-assembler-x64.h
index a294ad6..aedc3b9 100644
--- a/src/x64/macro-assembler-x64.h
+++ b/src/x64/macro-assembler-x64.h
@@ -582,6 +582,9 @@
   // Abort execution if argument is not a number. Used in debug code.
   void AbortIfNotNumber(Register object);
 
+  // Abort execution if argument is a smi. Used in debug code.
+  void AbortIfSmi(Register object);
+
   // Abort execution if argument is not a smi. Used in debug code.
   void AbortIfNotSmi(Register object);
 
@@ -829,6 +832,8 @@
   // Use --debug_code to enable.
   void Assert(Condition cc, const char* msg);
 
+  void AssertFastElements(Register elements);
+
   // Like Assert(), but always enabled.
   void Check(Condition cc, const char* msg);