Various bits are often duplicated in code objects.  For example,
sometimes names and varnames are equal.  In this case, we don't need two
objects since they are both const.  This patch implements a trivial fix
for this case.  However, there are more cases.  We should profile where
the memory is being used and do simple/cheap consolidations where
possible.  Another example would be a 1-element tuple containing:
(None,) for consts.

Some (all?) of these sorts of optimizations should probably be done in
the code object itself.