patch 9.1.0998: filetype: TI assembly files are not recognized

Problem:  filetype: TI assembly files are not recognized
Solution: inspect '*.sa' and assembly files and detect TI assembly
          files, include filetype plugin and syntax script for TI
          assembly files (Wu, Zhenyu)

closes: #15827

Signed-off-by: Wu, Zhenyu <wuzhenyu@ustc.edu>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/ftplugin/tiasm.vim b/runtime/ftplugin/tiasm.vim
new file mode 100644
index 0000000..13a3dc6
--- /dev/null
+++ b/runtime/ftplugin/tiasm.vim
@@ -0,0 +1,18 @@
+" Vim filetype plugin file
+" Language:	TI linear assembly language
+" Maintainer:	Wu, Zhenyu <wuzhenyu@ustc.edu>
+" Last Change:	2025 Jan 08
+
+if exists("b:did_ftplugin") | finish | endif
+let b:did_ftplugin = 1
+
+setlocal comments=:;
+setlocal commentstring=;\ %s
+
+let b:undo_ftplugin = "setl commentstring< comments<"
+
+if exists("loaded_matchit")
+  let b:match_words = '^\s\+\.if\>:^\s\+\.elseif:^\s\+\.else\>:^\s\+\.endif\>,^\s\+\.group:^\s\+\.gmember:^\s\+\.endgroup,^\s\+\.loop:^\s\+\.break:^\s\+\.endloop,^\s\+\.macro:^\s\+\.mexit:^\s\+\.endm,^\s\+\.asmfunc:^\s\+\.endasmfunc,^\s\+\.c\?struct:^\s\+\.endstruct,^\s\+\.c\?union:^\s\+\.endunion,^\s\+\.c\?proc:^\s\+\.return:^\s\+\.endproc'
+  let b:match_ignorecase = 1
+  let b:undo_ftplugin ..= " | unlet! b:match_ignorecase b:match_words"
+endif