The translator does better in a number of places when it
knows an AttrUnqiue Class* at translation time - even if it
doesnt know for sure that it will be defined when we enter the
tracelet. Now that we autoload (nearly) everything, we enter
a lot of tracelets where an AttrUnique Class* has been seen
(during warmup) but is not yet defined (in this request).
I added lookupUniqueClass while working on the new autoloader
to find such Classes, and allow us to do a better translation,
but never got around to using it.
mwilliams
f7b802c872