patch 8.2.1964: not all ConTeXt files are recognized

Problem:    Not all ConTeXt files are recognized.
Solution:   Add two patterns. (closes #7263)

Author: brammool

runtime/filetype.vim

@@ -1721,7 +1721,7 @@ au BufNewFile,BufRead *.latex,*.sty,*.dtx,*.ltx,*.bbl	setf tex
 au BufNewFile,BufRead *.tex			call dist#ft#FTtex()
 
 " ConTeXt
-au BufNewFile,BufRead *.mkii,*.mkiv,*.mkvi   setf context
+au BufNewFile,BufRead *.mkii,*.mkiv,*.mkvi,*.mkxl,*.mklx   setf context
 
 " Texinfo
 au BufNewFile,BufRead *.texinfo,*.texi,*.txi	setf texinfo

src/testdir/test_filetype.vim

@@ -110,7 +110,7 @@ let s:filename_checks = {
     \ 'conaryrecipe': ['file.recipe'],
     \ 'conf': ['auto.master'],
     \ 'config': ['configure.in', 'configure.ac', 'Pipfile', '/etc/hostname.file'],
-    \ 'context': ['tex/context/any/file.tex', 'file.mkii', 'file.mkiv', 'file.mkvi'],
+    \ 'context': ['tex/context/any/file.tex', 'file.mkii', 'file.mkiv', 'file.mkvi', 'file.mkxl', 'file.mklx'],
     \ 'cpp': ['file.cxx', 'file.c++', 'file.hh', 'file.hxx', 'file.hpp', 'file.ipp', 'file.moc', 'file.tcc', 'file.inl', 'file.tlh'],
     \ 'crm': ['file.crm'],
     \ 'crontab': ['crontab', 'crontab.file', '/etc/cron.d/file', 'any/etc/cron.d/file'],

src/version.c

@@ -750,6 +750,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1964,
 /**/
     1963,
 /**/