vim-patch:9.0.0479: in :def function all closures in loop get the sam… (#20220)

vim-patch:9.0.0479: in :def function all closures in loop get the same variables

Problem:    In a :def function all closures in a loop get the same variables.
Solution:   Use a separate list of variables for LOADOUTER and SAVEOUTER.
1aea184a0d

(note: patch description is wrong)

runtime/lua/vim/filetype.lua

@@ -1021,6 +1021,7 @@ local extension = {
   dsm = 'vb',
   ctl = 'vb',
   vbs = 'vb',
+  vdf = 'vdf',
   vdmpp = 'vdmpp',
   vpp = 'vdmpp',
   vdmrt = 'vdmrt',