patch 9.1.0011: regexp cannot match combining chars in collection

patch 9.1.0011: regexp cannot match combining chars in collection

Problem:  regexp cannot match combining chars in collection
Solution: Check for combining characters in regex collections for the
          NFA and BT Regex Engine

Also, while at it, make debug mode work again.

fixes #10286
closes: #12871

Signed-off-by: Christian Brabandt <cb@256bit.org>