transformations: Relax the rules for transformation finalizing.
The trns_chain data structure has a barely useful concept called
"finalization". In practice this is used to make sure that control
structures (e.g. DO IF) that are opened get closed (e.g. END IF). There
are currently some restrictions on finalizing: namely, transformations
can't be added after a chain is finalized. Since finalizers are barely
used, we can relax this restriction, which this commit does. This will be
used in an upcoming commit where the ability to add a transformation to a
finalized change becomes useful for a corner case.
projects / pspp / commit