vim-patch:9.1.0401: filetype: zsh module files are not recognized

Problem:  filetype: zsh module files are not recognized
Solution: Detect '*.mdh' and '*.epro' as C filetype, '*.mdd' as zsh
          filetype, determine zsh-modules '*.pro' from from it's content
          (Wu, Zhenyu)

closes: vim/vim#14737

887a38cee7

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

runtime/lua/vim/filetype.lua

@@ -248,6 +248,8 @@ local extension = {
   bzl = 'bzl',
   bazel = 'bzl',
   BUILD = 'bzl',
+  mdh = 'c',
+  epro = 'c',
   qc = 'c',
   cabal = 'cabal',
   cairo = 'cairo',
@@ -1206,6 +1208,7 @@ local extension = {
   zsh = 'zsh',
   zunit = 'zsh',
   ['zsh-theme'] = 'zsh',
+  mdd = 'zsh',
   vala = 'vala',
   web = detect.web,
   pl = detect.pl,

runtime/lua/vim/filetype/detect.lua

@@ -1141,12 +1141,14 @@ end
 --- Distinguish between "default", Prolog and Cproto prototype file.
 --- @type vim.filetype.mapfn
 function M.proto(_, bufnr)
-  -- Cproto files have a comment in the first line and a function prototype in
-  -- the second line, it always ends in ";".  Indent files may also have
-  -- comments, thus we can't match comments to see the difference.
-  -- IDL files can have a single ';' in the second line, require at least one
-  -- character before the ';'.
-  if getline(bufnr, 2):find('.;$') then
+  if getline(bufnr, 2):find('/%* Generated automatically %*/') then
+    return 'c'
+  elseif getline(bufnr, 2):find('.;$') then
+    -- Cproto files have a comment in the first line and a function prototype in
+    -- the second line, it always ends in ";".  Indent files may also have
+    -- comments, thus we can't match comments to see the difference.
+    -- IDL files can have a single ';' in the second line, require at least one
+    -- character before the ';'.
     return 'cpp'
   end
   -- Recognize Prolog by specific text in the first non-empty line;