This fixes a bug introduced in 2019-12-18T05:41:27Z!eggert@cs.ucla.edu,
an earlier patch that fixed dfa.c to not match invalid UTF-8.
Unfortunately that patch had a couple of typos when dfa.c is
matching against the regular expression ‘.’ (dot). One typo
caused dfa.c to incorrectly reject the valid UTF-8 sequences
(ED)(90-9F)(80-BF) corresponding to U+D400 through U+D7FF, which
are some Hangul Syllables and Hangul Jamo Extended-B. The other
typo caused dfa.c to incorrectly reject the valid sequences
(F4)(88-8F)(80-BF)(80-BF) which correspond to U+108000 through
U+10FFFF (Supplemental Private Use Area plane B).
* lib/dfa.c (utf8_classes): Fix typos.
* tests/test-dfa-match.sh: Test the fix.