Define ISO 639-3 "ltg" (Latgalian) and add ltg_LV locale

Resolves: BZ # 31411

References:
https://iso639-3.sil.org/code/ltg
https://en.wikipedia.org/wiki/Latgalian_language
https://github.com/unicode-org/cldr/blob/main/common/main/ltg.xml

locale/iso-639.def

@@ -277,6 +277,7 @@ DEFINE_LANGUAGE_CODE3 ("Ladino", lad, lad)
 DEFINE_LANGUAGE_CODE3 ("Lahnda", lah, lah)
 DEFINE_LANGUAGE_CODE3 ("Lamba", lam, lam)
 DEFINE_LANGUAGE_CODE ("Lao", lo, lao, lao)
+DEFINE_LANGUAGE_CODE3 ("Latgalian", ltg, ltg)
 DEFINE_LANGUAGE_CODE ("Latin", la, lat, lat)
 DEFINE_LANGUAGE_CODE ("Latvian", lv, lav, lav)
 DEFINE_LANGUAGE_CODE3 ("Lezghian", lez, lez)

localedata/Makefile

@@ -92,6 +92,7 @@ test-input := \
   ky_KG.UTF-8 \
   ln_CD.UTF-8 \
   lt_LT.UTF-8 \
+  ltg_LV.UTF-8 \
   lv_LV.UTF-8 \
   mdf_RU.UTF-8 \
   mi_NZ.UTF-8 \
@@ -358,6 +359,7 @@ LOCALES := \
   ky_KG.UTF-8 \
   ln_CD.UTF-8 \
   lt_LT.UTF-8 \
+  ltg_LV.UTF-8 \
   lv_LV.UTF-8 \
   mdf_RU.UTF-8 \
   mi_NZ.UTF-8 \

localedata/SUPPORTED

@@ -312,6 +312,7 @@ ln_CD/UTF-8 \
 lo_LA/UTF-8 \
 lt_LT.UTF-8/UTF-8 \
 lt_LT/ISO-8859-13 \
+ltg_LV.UTF-8/UTF-8 \
 lv_LV.UTF-8/UTF-8 \
 lv_LV/ISO-8859-13 \
 lzh_TW/UTF-8 \

localedata/locales/ltg_LV

@@ -0,0 +1,144 @@
+comment_char %
+escape_char /
+
+% This file is part of the GNU C Library and contains locale data.
+% The Free Software Foundation does not claim any copyright interest
+% in the locale data contained in this file.  The foregoing does not
+% affect the license of the GNU C Library as a whole.  It does not
+% exempt you from the conditions of the license if your use would
+% otherwise be governed by that license.
+
+LC_IDENTIFICATION
+title      "Latgalian locale for Latvia"
+source     "Latvian Standard LVS 24:1993"
+address    ""
+contact    "laka@laka.lv"
+email      "bug-glibc-locales@gnu.org"
+tel        ""
+fax        ""
+language   "Latgalian"
+territory  "Latvia"
+revision   "1.0"
+date       "2024-02-24"
+
+category "i18n:2012";LC_IDENTIFICATION
+category "i18n:2012";LC_CTYPE
+category "i18n:2012";LC_COLLATE
+category "i18n:2012";LC_TIME
+category "i18n:2012";LC_NUMERIC
+category "i18n:2012";LC_MONETARY
+category "i18n:2012";LC_MESSAGES
+category "i18n:2012";LC_PAPER
+category "i18n:2012";LC_NAME
+category "i18n:2012";LC_ADDRESS
+category "i18n:2012";LC_TELEPHONE
+category "i18n:2012";LC_MEASUREMENT
+END LC_IDENTIFICATION
+
+LC_COLLATE
+copy "lv_LV"
+END LC_COLLATE
+
+LC_CTYPE
+copy "lv_LV"
+END LC_CTYPE
+
+LC_MONETARY
+copy "lv_LV"
+END LC_MONETARY
+
+LC_NUMERIC
+copy "lv_LV"
+END LC_NUMERIC
+
+% Months, LVS 24:1993 6.3.3.
+% janvars, februars, marts, apreļs, majs, juņs, juļs, augusts, septembris, oktobris, novembris, decembris
+% LV:  jan, feb, mar, apr, mai, jūn, jūl, aug, sep, okt, nov, dec
+% LTG: jan, feb, mar, apr, maj, juņ, juļ, aug, sep, okt, nov, dec
+
+% Dienas, LVS 24:1993 6.3.1.
+% pyrmūdīne, ūtardīne, trešdīne, catūrtdīne, pīktdīne, sastdīne, svātdīne
+% LV:  P, O, T, C, Pk, S, Sv
+% LTG: P, Ū, T, C, Pk, S, Sv
+% LV:  Pr, Ot, Tr, Ce, Pk, Se, Sv
+% LTG: Pr, Ūt, Tr, Ca, Pk, Sa, Sv
+
+LC_TIME
+abday    "Sv";"P ";/
+         "Ū ";"T ";/
+         "C ";"Pk";/
+         "S "
+day      "svātdīne";/
+         "pyrmūdīne";/
+         "ūtardīne";/
+         "trešdīne";/
+         "catūrtdīne";/
+         "pīktdīne";/
+         "sastdīne"
+abmon    "jan";"feb";/
+         "mar";"apr";/
+         "maj";"juņ";/
+         "juļ";"aug";/
+         "sep";"okt";/
+         "nov";"dec"
+mon      "janvars";/
+         "februars";/
+         "marts";/
+         "apreļs";/
+         "majs";/
+         "juņs";/
+         "juļs";/
+         "augusts";/
+         "septembris";/
+         "oktobris";/
+         "novembris";/
+         "decembris"
+
+% otrdiena, 1993. gada  5. janvāris, plkst. 17 un 15 minūtes
+d_t_fmt  "%A, %Y. goda %e. %B, plkst. %H : %M"
+% Pk, 1993. 17. dec
+% 1993.06.17
+d_fmt    "%Y.%m.%d."
+% 18:59:32
+t_fmt    "%T"
+am_pm    "";""
+t_fmt_ampm  ""
+week 7;19971130;1
+first_weekday 2
+END LC_TIME
+
+LC_MESSAGES
+yesexpr "^[+1JjYy]"
+noexpr  "^[-0Nn]"
+yesstr  "jā"
+nostr   "nā"
+END LC_MESSAGES
+
+LC_PAPER
+copy "i18n"
+END LC_PAPER
+
+LC_TELEPHONE
+copy "lv_LV"
+END LC_TELEPHONE
+
+LC_MEASUREMENT
+copy "i18n"
+END LC_MEASUREMENT
+
+LC_NAME
+copy "lv_LV"
+END LC_NAME
+
+LC_ADDRESS
+postal_fmt    "%f%N%a%N%d%N%b%N%s %h %e %r%N%z %T%N%c%N"
+country_name "Latvija"
+country_ab2 "LV"
+country_ab3 "LVA"
+country_num 428
+country_car "LV"
+% latgaliešu valoda
+lang_name    "latgalīšu"
+lang_term    "ltg"
+lang_lib    "ltg"
+END LC_ADDRESS

localedata/ltg_LV.UTF-8.in

@@ -0,0 +1,162 @@
+a
+A
+å
+Å
+aa
+Aa
+ab
+Ab
+æ
+Æ
+ā
+Ā
+āa
+Āa
+āb
+Āb
+c
+C
+ç
+Ç
+č
+Č
+ča
+Ča
+čb
+Čb
+D
+e
+E
+ē
+Ē
+ēa
+Ēa
+ēb
+Ēb
+g
+G
+ģ
+Ģ
+ģa
+Ģa
+ģb
+Ģb
+h
+H
+i
+I
+ia
+Ia
+ib
+Ib
+y
+Y
+ya
+Ya
+yb
+Yb
+ī
+Ī
+īa
+Īa
+īb
+Īb
+ĵ
+Ĵ
+ĵa
+Ĵa
+ĵb
+Ĵb
+k
+K
+ķ
+Ķ
+ķa
+Ķa
+ķb
+Ķb
+l
+L
+ļ
+Ļ
+ļa
+Ļa
+ļb
+Ļb
+m
+M
+n
+N
+ņ
+Ņ
+ņa
+Ņa
+ņb
+Ņb
+o
+O
+ø
+Ø
+ō
+Ō
+ōa
+Ōa
+ōb
+Ōb
+r
+R
+ra
+Ra
+rb
+Rb
+ŗ
+Ŗ
+ŗa
+Ŗa
+ŗb
+Ŗb
+s
+S
+sa
+Sa
+sb
+Sb
+š
+Š
+ša
+Ša
+šb
+Šb
+t
+T
+u
+U
+ū
+Ū
+ūa
+Ūa
+ūb
+Ūb
+x
+z
+Z
+ź
+Ź
+za
+Za
+zb
+Zb
+ȥ
+Ȥ
+ž
+Ž
+ža
+Ža
+žb
+Žb
+ʒ
+Ʒ
+ʒa
+Ʒa
+ʒb
+Ʒb