Add some transliterations for mathematical symbols.

Based on <https://sourceware.org/bugzilla/show_bug.cgi?id=23132>
and the translit_neutral change in
<https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=513aaa0d782f8fae36732d06ca59d658149f0139>.

Reported by Mike Fulton <mikefultonpersonal@gmail.com> in
<https://lists.gnu.org/archive/html/bug-gnu-libiconv/2023-03/msg00002.html>.

* lib/translit.def: Add a couple of transliterations in the range
U+27C0..U+29FF.
* NEWS: Mention it.
3 files changed