Fixes k-takata/Onigmo#92.

This fix was ported from oniguruma:
https://github.com/kkos/oniguruma/commit/257082dac8c6019198b56324012f0bd1830ff4ba

https://github.com/k-takata/Onigmo/commit/b1a5445fbeba97b3e94a733c2ce11c033453af73

See <https://bugs.ruby-lang.org/issues/19417#note-3>.

https://unicode.org/reports/tr18/#word states word should match join_control chars.

It did not previously:

```ruby
[*0x0..0xD799, *0xE000..0x10FFFF].map { |n| n.chr 'utf-8' } => all_chars
all_chars.grep(/\p{join_control}/) => jc
jc.count # => 2
jc.grep(/\p{word}/).count # => 0
```
[Backport #19417]

---

Backporting note: I regenerated `enc/unicode/15.0.0/name2ctype.h` using
`make update-unicode`.

https://bugs.ruby-lang.org/issues/20478