Add Mongolian language environments

* lisp/language/misc-lang.el ("Mongolian-traditional"):
* lisp/language/cyrillic.el ("Mongolian-cyrillic"): New
language environments.

* etc/HELLO: Add Mongolian Traditional.
* etc/NEWS: Announce the new language environments.

(Bug#63028)

etc/HELLO

@@ -89,7 +89,9 @@ Mathematics	∀ p ∈ world • hello p  □
 Meetei Mayek (ꯃꯤꯇꯩ ꯃꯌꯦꯛ)	ꯈꯨꯔꯨꯝꯖꯔꯤ
 Mende Kikakui (𞠀𞠁𞠂)	𞠛𞠉
 Modi (𑘦𑘻𑘚𑘲)	𑘡𑘦𑘭𑘿𑘎𑘰𑘨
-Mongolian (монгол хэл)	Сайн байна уу?
+Mongolian Cyrillic (монгол хэл)	Сайн байна уу?
+Mongolian Traditional (ᠮᠣᠩᠭᠣᠯ ᠪᠢᠴᠢᠭ᠋)	ᠰᠠᠶᠢᠨ ᠪᠠᠶᠢᠨ᠎ᠠ ᠤᠤ?
+
 Northern Thai (ᨣᩣᩴᨾᩮᩬᩥᨦ / ᨽᩣᩈᩣᩃ᩶ᩣ᩠ᨶᨶᩣ)	ᩈ᩠ᩅᩢᩔ᩠ᨯᩦᨣᩕᩢ᩠ᨸ
 Norwegian (norsk)	Hei / God dag
 Odia (ଓଡ଼ିଆ)	ନମସ୍କାର

etc/NEWS

@@ -1546,6 +1546,10 @@ environments are:
 
  Coptic script and language environment
 
+ Mongolian-traditional script and language environment
+
+ Mongolian-cyrillic language environment
+
 ---
 *** The "Oriya" language environment was renamed to "Odia".
 This is to follow the change in the official name of the script.  The
@@ -1587,7 +1591,8 @@ script.
 ---
 *** New input method 'cyrillic-mongolian'.
 This input method is for typing in the Mongolian language using the
-Cyrillic script.
+Cyrillic script.  It is the default input method for the new
+Mongolian-cyrillic language environment, see above.
 
 
 * Changes in Specialized Modes and Packages in Emacs 29.1

lisp/language/cyrillic.el

@@ -256,6 +256,16 @@ Support for Russian using koi8-r and the russian-computer input method.")
 \(The name Belarusian replaced Byelorussian in the early 1990s.)"))
  '("Cyrillic"))
 
+;; The Mongolian-traditional language environment is in misc-lang.el.
+(set-language-info-alist
+ "Mongolian-cyrillic" '((coding-system utf-8)
+	                (coding-priority utf-8)
+	                (input-method . "cyrillic-mongolian")
+		        (sample-text . "Mongolian (монгол хэл)	Сайн байна уу?")
+	                (documentation
+		         . "Support for Mongolian language with Cyrillic alphabet."))
+ '("Cyrillic"))
+
 (provide 'cyrillic)
 
 ;;; cyrillic.el ends here

lisp/language/misc-lang.el

@@ -343,6 +343,17 @@ language environment."))
 ;; Traditional Mongolian
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 
+;; The Mongolian-cyrillic language environment is in cyrillic.el.
+(set-language-info-alist
+ "Mongolian-traditional" '((coding-system utf-8)
+	                   (coding-priority utf-8)
+	                   ; (input-method . "FIXME")
+		           (sample-text . "Mongolian Traditional (ᠮᠣᠩᠭᠣᠯ ᠪᠢᠴᠢᠭ᠋)	ᠰᠠᠶᠢᠨ ᠪᠠᠶᠢᠨ᠎ᠠ ᠤᠤ?")
+	                   (documentation
+		            . "Support for Mongolian language with traditional script."))
+ '("Misc"))
+
+;; Composition rules for Mongolian Traditional script.
 (set-char-table-range
  composition-function-table
  '(#x1820 . #x18AF)
@@ -352,7 +363,6 @@ language environment."))
        (vector "[\u1820-\u18AF\u202F\u180B-\u180F\u1807]+"
                0 'font-shape-gstring)))
 
-
 (provide 'misc-lang)
 
 ;;; misc-lang.el ends here