Remove-fgl-binder-meta
Deregister a binder metafunction for use in FGL.
This is invoked as follows:
(remove-fgl-binder-meta trigger-fn meta-fn)
This invocation removes the entry in the fgl-rewrite-rules table that
allows meta-fn to be used in symbolic interpretation of trigger-fn
binder invocations, preventing the use of meta-fn.