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/syntax/opencl.vim b/runtime/syntax/opencl.vim
new file mode 100644
index 0000000..c237aa3
--- /dev/null
+++ b/runtime/syntax/opencl.vim
@@ -0,0 +1,13 @@
+" Vim syntax file
+" Language:	OpenCL
+" Last Change:	2024 Nov 19
+" Maintainer:	Wu, Zhenyu <wuzhenyu@ustc.edu>
+
+if exists("b:current_syntax")
+  finish
+endif
+
+" TODO: support openCL specific keywords
+runtime! syntax/c.vim
+
+let current_syntax = "opencl"