patch 9.1.0591: filetype: *.wl files are not recognized

Problem:  filetype: *.wl files are not recognized
Solution: Detect '*.wl' files as Mathematica package files
          (Jonas Dujava)

closes: #15269

Signed-off-by: Jonas Dujava <jonas.dujava@gmail.com>
Signed-off-by: Doug Kearns <dougkearns@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/filetype.vim b/runtime/filetype.vim
index 6ee4172..0cc0a62 100644
--- a/runtime/filetype.vim
+++ b/runtime/filetype.vim
@@ -1418,8 +1418,8 @@
 " Mathematica, Matlab, Murphi, Objective C or Octave
 au BufNewFile,BufRead *.m			call dist#ft#FTm()
 
-" Mathematica notebook
-au BufNewFile,BufRead *.nb			setf mma
+" Mathematica notebook and package files
+au BufNewFile,BufRead *.nb,*.wl			setf mma
 
 " Maya Extension Language
 au BufNewFile,BufRead *.mel			setf mel
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index 5cace2e2..edb9849 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -471,7 +471,7 @@
     mgp: ['file.mgp'],
     mib: ['file.mib', 'file.my'],
     mix: ['file.mix', 'file.mixal'],
-    mma: ['file.nb'],
+    mma: ['file.nb', 'file.wl'],
     mmp: ['file.mmp'],
     modconf: ['/etc/modules.conf', '/etc/modules', '/etc/conf.modules', '/etc/modprobe.file', 'any/etc/conf.modules', 'any/etc/modprobe.file', 'any/etc/modules', 'any/etc/modules.conf'],
     modula3: ['file.m3', 'file.mg', 'file.i3', 'file.ig', 'file.lm3'],
diff --git a/src/version.c b/src/version.c
index ae351cf..b9d85a6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    591,
+/**/
     590,
 /**/
     589,