patch 9.1.1186: filetype: help files in git repos are not detected

Problem:  filetype: help files in git repos are not detected
Solution: detect */doc/*.txt files as help if they end with a help
          modeline, even if 'modeline' is off

Here's how I checked that this would still detect vim's own help files
correctly:

$ find . -type f -path '*/doc/*.txt' \
> -exec awk '{ } ENDFILE { print FILENAME ":" $0; }' '{}' + |
> grep -v 'vim:.*\<\(ft\|filetype\)=help\>'
./src/libvterm/doc/seqs.txt: 23    DECSM 42         = DECNRCM, national/multinational character

closes: #16817

Signed-off-by: David Mandelberg <david@mandelberg.org>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/test_filetype.vim b/src/testdir/test_filetype.vim
index b6beb3f..521c0f6 100644
--- a/src/testdir/test_filetype.vim
+++ b/src/testdir/test_filetype.vim
@@ -919,8 +919,6 @@
           '.zcompdump', '.zlogin', '.zlogout', '.zshenv', '.zshrc', '.zsh_history',
           '.zcompdump-file', '.zlog', '.zlog-file', '.zsh', '.zsh-file',
           'any/etc/zprofile', 'zlog', 'zlog-file', 'zsh', 'zsh-file'],
-
-    help: [$VIMRUNTIME .. '/doc/help.txt'],
     }
 enddef
 
@@ -1626,6 +1624,23 @@
   filetype off
 endfunc
 
+func Test_help_file()
+  filetype on
+  call assert_true(mkdir('doc', 'pR'))
+
+  call writefile(['some text', 'vim:ft=help:'], 'doc/help.txt', 'D')
+  split doc/help.txt
+  call assert_equal('help', &filetype)
+  bwipe!
+
+  call writefile(['some text'], 'doc/nothelp.txt', 'D')
+  split doc/nothelp.txt
+  call assert_notequal('help', &filetype)
+  bwipe!
+
+  filetype off
+endfunc
+
 func Test_hook_file()
   filetype on
 
diff --git a/src/version.c b/src/version.c
index 1bfcbcb..5536a9b 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1186,
+/**/
     1185,
 /**/
     1184,