Emit meta for empty list.
nthnext.
not=.
Various seq functions.
comp and partial.
every-pred and some-fn.
complement.
juxt.
integer?, even?, odd?.
to-array.
distinct.
update-in, assoc-in, get-in.
aclone, amap, areduce, and proper aset.
sort.
sort-by.
shuffle.
dotimes.
instance?.

We put a constructor field into the ptable which points to the
constructor function, which also doubles as the first-class type.
delay.
Fix Atom printing.