fixed bug: grep '.' didn't match some Hangul Syllables etc.

[Paul Eggert]

While looking into a TZDB problem I noticed that GNU grep mistakenly 
reported that some files were not UTF-8 even though they were. One can 
reproduce the problem in Gnulib by running the command:

grep -v '^.*$' gnulib/tests/uninorm/NormalizationTest.txt

This should output nothing, but outputs 943 lines containing Hangul 
syllables.

I tracked this down to a Gnulib bug I introduced in 2019, and fixed it 
in Gnulib here:

https://git.savannah.gnu.org/cgit/gnulib.git/commit/?id=b19a10775e54f8ed17e3a8c08a72d261d8c26244

and in Grep by installing the attached patches.

0001-build-update-gnulib-submodule-to-latest.patch
Description: Text Data

0002-grep-fix-bug-with-.-and-some-Hangul-Syllables.patch
Description: Text Data