vim-patch:9.1.0982: TI linker files are not recognized

Problem:  TI linker files are not recognized
Solution: inspect '*.cmd' files and detect TI linker files
          as 'lnk' filetype, include a lnk ftplugin and syntax
          script (Wu, Zhenyu)

closes: vim/vim#16320

39a4eb0b2c

Co-authored-by: Wu, Zhenyu <wuzhenyu@ustc.edu>

runtime/lua/vim/filetype.lua

@@ -1393,7 +1393,7 @@ local extension = {
   txt = detect.txt,
   xml = detect.xml,
   y = detect.y,
-  cmd = detect_line1('^/%*', 'rexx', 'dosbatch'),
+  cmd = detect.cmd,
   rul = detect.rul,
   cpy = detect_line1('^##', 'python', 'cobol'),
   dsl = detect_line1('^%s*<!', 'dsl', 'structurizr'),

runtime/lua/vim/filetype/detect.lua

@@ -219,6 +219,24 @@ function M.cls(_, bufnr)
   return 'st'
 end
 
+--- *.cmd is close to a Batch file, but on OS/2 Rexx files and TI linker command files also use *.cmd.
+--- lnk: `/* comment */`, `// comment`, and `--linker-option=value`
+--- rexx: `/* comment */`, `-- comment`
+--- @type vim.filetype.mapfn
+function M.cmd(_, bufnr)
+  local lines = table.concat(getlines(bufnr, 1, 20))
+  if matchregex(lines, [[MEMORY\|SECTIONS\|\%(^\|\n\)--\S\|\%(^\|\n\)//]]) then
+    return 'lnk'
+  else
+    local line1 = getline(bufnr, 1)
+    if line1:find('^/%*') then
+      return 'rexx'
+    else
+      return 'dosbatch'
+    end
+  end
+end
+
 --- @type vim.filetype.mapfn
 function M.conf(path, bufnr)
   if fn.did_filetype() ~= 0 or path:find(vim.g.ft_ignore_pat) then