patch 8.2.1544: cannot translate messages in a Vim script

Problem:    Cannot translate messages in a Vim script.
Solution:   Add gettext().  Try it out for a few messages in the options
            window.

runtime/doc/eval.txt

@@ -2546,6 +2546,7 @@ gettabvar({nr}, {varname} [, {def}])
 gettabwinvar({tabnr}, {winnr}, {name} [, {def}])
 				any	{name} in {winnr} in tab page {tabnr}
 gettagstack([{nr}])		Dict	get the tag stack of window {nr}
+gettext({text})			String	lookup translation of {text}
 getwininfo([{winid}])		List	list of info about each window
 getwinpos([{timeout}])		List	X and Y coord in pixels of the Vim window
 getwinposx()			Number	X coord in pixels of the Vim window
@@ -5827,6 +5828,19 @@ gettagstack([{nr}])					*gettagstack()*
 		Can also be used as a |method|: >
 			GetWinnr()->gettagstack()
 
+
+gettext({text})						*gettext()*
+		Translate {text} if possible.
+		This is mainly for use in the distributed Vim scripts.  When
+		generating message translations the {text} is extracted by
+		xgettext, the translator can add the translated message in the
+		.po file and Vim will lookup the translation when gettext() is
+		called.
+		For {text} double quoted strings are preferred, because
+		xgettext does not understand escaping in single quoted
+		strings.
+
+
 getwininfo([{winid}])					*getwininfo()*
 		Returns information about windows as a |List| with Dictionaries.
 

runtime/doc/usr_41.txt

@@ -628,6 +628,7 @@ String manipulation:					*string-functions*
 	execute()		execute an Ex command and get the output
 	win_execute()		like execute() but in a specified window
 	trim()			trim characters from a string
+	gettext()		lookup message translation
 
 List manipulation:					*list-functions*
 	get()			get an item without error for wrong index