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.
diff --git a/src/po/fixfilenames.vim b/src/po/fixfilenames.vim
new file mode 100644
index 0000000..65d448c
--- /dev/null
+++ b/src/po/fixfilenames.vim
@@ -0,0 +1,13 @@
+" Invoked with the name "vim.pot" and a list of Vim script names.
+" Converts them to a .js file, stripping comments, so that xgettext works.
+
+set shortmess+=A
+
+for name in argv()[1:]
+  let jsname = fnamemodify(name, ":t:r") .. ".js"
+  exe "%s+" .. jsname .. "+" .. name .. "+"
+endfor
+
+write
+last
+quit