Regexp with word-boundary followed by unicode character doesn't work in 19, 21

[Mark Reinhold]

2023/12/15 13:50:19 -0500, stefan at selessia.com:
> I apologize in advance if this isn't the right forum for posting a bug
> report. If not, feel free to point me in the right direction!

core-libs-dev at openjdk.org.

- Mark