Update V8 to r5447 as required by WebKit r67908

Change-Id: I5af6ccf18523cb7e28460e6bbc044444256cdb97
diff --git a/src/full-codegen.h b/src/full-codegen.h
index 840c825..ab0fd36 100644
--- a/src/full-codegen.h
+++ b/src/full-codegen.h
@@ -381,6 +381,14 @@
 #undef EMIT_INLINE_RUNTIME_CALL
 
   // Platform-specific code for loading variables.
+  void EmitLoadGlobalSlotCheckExtensions(Slot* slot,
+                                         TypeofState typeof_state,
+                                         Label* slow);
+  MemOperand ContextSlotOperandCheckExtensions(Slot* slot, Label* slow);
+  void EmitDynamicLoadFromSlotFastCase(Slot* slot,
+                                       TypeofState typeof_state,
+                                       Label* slow,
+                                       Label* done);
   void EmitVariableLoad(Variable* expr, Expression::Context context);
 
   // Platform-specific support for allocating a new closure based on
@@ -500,6 +508,9 @@
   // in v8::internal::Context.
   void LoadContextField(Register dst, int context_index);
 
+  // Create an operand for a context field.
+  MemOperand ContextOperand(Register context, int context_index);
+
   // AST node visit functions.
 #define DECLARE_VISIT(type) virtual void Visit##type(type* node);
   AST_NODE_LIST(DECLARE_VISIT)