vim-patch:9.0.2011: INI files not detected

Problem:  INI files not detected
Solution: detect uppercase .INI as dosini files

It previo~1 only worked for lower-case .ini files, but upperc~1 .INI is
also somewhat common on account of DOS' old 8.3 upperc~2 only filena~1.

closes: vim/vim#13316

4a82bdfaa8

Co-authored-by: Martin Tournoij <martin@arp242.net>

runtime/lua/vim/filetype.lua

@@ -352,6 +352,7 @@ local extension = {
   bat = 'dosbatch',
   wrap = 'dosini',
   ini = 'dosini',
+  INI = 'dosini',
   vbp = 'dosini',
   dot = 'dot',
   gv = 'dot',