patch 9.1.0876: filetype: openCL files are not recognized

Problem:  filetype: openCL files are not recognized
Solution: detect '*.cl' files as opencl or lisp filetype,
          include a opencl syntax and filetype plugin (Wu, Zhenyu)

closes: #15825

Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index eab9d1e..17d6a44 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -425,7 +425,7 @@
     limits: ['/etc/limits', '/etc/anylimits.conf', '/etc/anylimits.d/file.conf', '/etc/limits.conf', '/etc/limits.d/file.conf', '/etc/some-limits.conf', '/etc/some-limits.d/file.conf', 'any/etc/limits', 'any/etc/limits.conf', 'any/etc/limits.d/file.conf', 'any/etc/some-limits.conf', 'any/etc/some-limits.d/file.conf'],
     liquidsoap: ['file.liq'],
     liquid: ['file.liquid'],
-    lisp: ['file.lsp', 'file.lisp', 'file.asd', 'file.el', 'file.cl', '.emacs', '.sawfishrc', 'sbclrc', '.sbclrc', 'file.stsg', 'any/local/share/supertux2/config'],
+    lisp: ['file.lsp', 'file.lisp', 'file.asd', 'file.el', '.emacs', '.sawfishrc', 'sbclrc', '.sbclrc', 'file.stsg', 'any/local/share/supertux2/config'],
     lite: ['file.lite', 'file.lt'],
     litestep: ['/LiteStep/any/file.rc', 'any/LiteStep/any/file.rc'],
     logcheck: ['/etc/logcheck/file.d-some/file', '/etc/logcheck/file.d/file', 'any/etc/logcheck/file.d-some/file', 'any/etc/logcheck/file.d/file'],
@@ -1198,6 +1198,22 @@
   filetype off
 endfunc
 
+func Test_cl_file()
+  filetype on
+
+  call writefile(['/*', ' * Xfile.cl', ' */', 'int f() {}'], 'Xfile.cl')
+  split Xfile.cl
+  call assert_equal('opencl', &filetype)
+  bwipe!
+
+  call writefile(['()'], 'Xfile.cl')
+  split Xfile.cl
+  call assert_equal('lisp', &filetype)
+  bwipe!
+
+  filetype off
+endfunc
+
 func Test_d_file()
   filetype on
 
diff --git a/src/version.c b/src/version.c
index ed84122..99fbbe8 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    876,
+/**/
     875,
 /**/
     874,