Lexicon needs to be able to obtain the field number
that contains a classic Fileman cross-reference by
a direct global read of the Lexicon's Data Dictionary
(DD) 0 node, 'IX' subscripts.
The Lexicon has become so large that conventional
Re-indexing by Kill/Set logic needs to be replaced
with Index Repair logic, avoiding the killing of a
cross-reference and allowing users to stay on the
system without loss of access to the Lexicon package.