Bug 271905

There seem to be a regression in version 13 of FreeBSD affecting
both basic and extended regular expression processing.

Illustration of problem (grep):

        $ uname -a 
        FreeBSD 13.2-RELEASE releng/13.2-n254617-525ecfdad597 GENERIC

        $ time grep -E '(wordorphrase|differentword)' 150MB-file >/dev/null

        real    0m54.565s
        user    0m54.372s
        sys     0m0.173s

should not take almost a minute to search 150MB file! 
Even worse is 

        $ time grep -i 'differentword' 150MB-file >/dev/null

        real    0m28.060s
        user    0m28.016s
        sys     0m0.038s

almost 30 sek to do a case-insensitive search on a 150MB
text file - compared to:

        $ time grep 'differentword' 150MB-file >/dev/null

        real    0m0.210s
        user    0m0.178s
        sys     0m0.032s

which runs at normal speed.

This all was fine on 12.3 and 12.4  - For example:

        $ uname -a
        FreeBSD 12.3-RELEASE-p11 GENERIC

        $ time grep -E '(wordorphrase|differentword)' 150MB-file >/dev/null

        real    0m0.290s
        user    0m0.219s
        sys     0m0.071s