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/runtime/ftplugin/opencl.vim b/runtime/ftplugin/opencl.vim
new file mode 100644
index 0000000..e8570fb
--- /dev/null
+++ b/runtime/ftplugin/opencl.vim
@@ -0,0 +1,12 @@
+" Vim filetype plugin file
+" Language:	OpenCL
+" Maintainer:	Wu, Zhenyu <wuzhenyu@ustc.edu>
+" Last Change:	2024 Nov 19
+
+if exists("b:did_ftplugin") | finish | endif
+let b:did_ftplugin = 1
+
+setlocal comments=sO:*\ -,mO:*\ \ ,exO:*/,s1:/*,mb:*,ex:*/,:///,://
+setlocal commentstring=/*\ %s\ */ define& include&
+
+let b:undo_ftplugin = "setl commentstring< comments<"