patch 9.1.1081: has('bsd') is true for GNU/Hurd

Problem:  has('bsd') is true for GNU/Hurd
Solution: exclude GNU/Hurd from BSD feature flag
          (Zhaoming Luo)

GNU/Hurd, like Mac OS X, is a BSD-based system. It should exclude
has('bsd') feature just like what Mac OS X does. The __GNU__ pre-defined
macro indicates it's compiled for GNU/Hurd.

closes: #16580

Signed-off-by: Zhaoming Luo <zhmingluo@163.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/builtin.txt b/runtime/doc/builtin.txt
index 39ff14e..e2d2f43 100644
--- a/runtime/doc/builtin.txt
+++ b/runtime/doc/builtin.txt
@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2025 Feb 02
+*builtin.txt*	For Vim version 9.1.  Last change: 2025 Feb 06
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -12750,6 +12750,7 @@
 haiku			Haiku version of Vim.
 hangul_input		Compiled with Hangul input support. |hangul|
 hpux			HP-UX version of Vim.
+hurd			GNU/Hurd version of Vim
 iconv			Can use iconv() for conversion.
 insert_expand		Compiled with support for CTRL-X expansion commands in
 			Insert mode. (always true)