When fully building the reflection info in TClass, a deserialization
could be triggered, which may result in request for building the
reflection info for the same TClass. This in turn will clear the caches
for the TClass in-flight and cause null ptr derefs.

Up for discussion (ASAP):FIXME: This is a quick fix, solving most of the issues. The actual
question is: Shouldn't TClass provide a lock mechanism on update or lock
itself until the update is done.

Thanks to Axel for the help.