Avoid TLS accesses in Object::Lookup and Object::GetPrototype.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index f2407f879453063a7c3c344b76f16f9f7aea1542..914a245483d33136bc2a7e71f7cf6b2cc574bd29 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -1019,7 +1019,7 @@ class Object : public MaybeObject {
                                                       uint32_t index);
 
   // Return the object's prototype (might be Heap::null_value()).
-  Object* GetPrototype();
+  Object* GetPrototype(Isolate* isolate);
 
   // Returns the permanent hash code associated with this object depending on
   // the actual object type.  Might return a failure in case no hash was