PRED_SPLIT produces false negative results for XCFA

[leventeBajczi]

There are wrong results with the current version (5.1.1) of Theta.
See results:
split.zip
Ignore floats-cbmc-regression/float8.yml in the results, that has a different root cause.

[leventeBajczi]

Until this is fixed, the frontend rejects the --domain PRED_SPLIT argument with the message

Validation failed for rule NoPredSplitUntilFixed(https://github.com/ftsrg/theta/issues/267).

[leventeBajczi]

It seems like this issue exists only with lazy pruning.