Several recent changes to named references, particularly the fixing of
reference targets at the scope of declaration, have made it impossible
to use the module PARAMDEF() macro to create named references at
module load that refer to locals at expansion time.

The attached patch removes the global partab namerefs affected by
this, and instead explicitly creates them as locals in the
ksh93_wrapper() callback, so that they come and go in the appropriate
scopes.

This is mildly unsatisfying because it leaves a couple of specials at
global scope, mostly for ease of instantiation, that really should
also be locals.  Might revisit that later.