Upgrade V8 to 5.1.281.57  DO NOT MERGE

FPIIM-449

Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
(cherry picked from commit 3b9bc31999c9787eb726ecdbfd5796bfdec32a18)
diff --git a/src/compiler/ast-graph-builder.h b/src/compiler/ast-graph-builder.h
index 6cff237..e206db0 100644
--- a/src/compiler/ast-graph-builder.h
+++ b/src/compiler/ast-graph-builder.h
@@ -419,11 +419,20 @@
   void VisitTypeof(UnaryOperation* expr);
   void VisitNot(UnaryOperation* expr);
 
+  // Dispatched from VisitTypeof, VisitLiteralCompareTypeof.
+  void VisitTypeofExpression(Expression* expr);
+
   // Dispatched from VisitBinaryOperation.
   void VisitComma(BinaryOperation* expr);
   void VisitLogicalExpression(BinaryOperation* expr);
   void VisitArithmeticExpression(BinaryOperation* expr);
 
+  // Dispatched from VisitCompareOperation.
+  void VisitLiteralCompareNil(CompareOperation* expr, Expression* sub_expr,
+                              Node* nil_value);
+  void VisitLiteralCompareTypeof(CompareOperation* expr, Expression* sub_expr,
+                                 Handle<String> check);
+
   // Dispatched from VisitForInStatement.
   void VisitForInAssignment(Expression* expr, Node* value,
                             const VectorSlotPair& feedback,