Jolt numbers don't overflow, so +'/-'/*'/inc'/dec' and the whole unchecked-*
family are just the checked ops — now one-line defs in core/20-coll.clj
instead of ~25 seed bindings. int? and num move the same way.
unchecked-divide-int now goes through quot, so dividing by zero throws like
the JVM instead of silently truncating infinity. unchecked-int/long gain
char handling via int, matching Clojure ((unchecked-int \a) => 97). The
masking byte/short/char coercions are not aliases and stay in the seed for
a later round.
Also drops a second duplicate set of unchecked defns that was shadowing the
first at module load.
9ac0f54e72