[newlib-cygwin] Cygwin: _pipe: add a comment

[Corinna Vinschen]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=9cfbb5aa82fc9ff49b1468bfad9d446eecb207c0

commit 9cfbb5aa82fc9ff49b1468bfad9d446eecb207c0
Author: Corinna Vinschen <corinna@vinschen.de>
Date:   Tue Aug 31 10:50:23 2021 +0200

    Cygwin: _pipe: add a comment
    
    I wasted valuable minutes of my life just to find out why we export
    this weird version of pipe.  In the pre-2000 era the idea was Cygwin
    could be used as drop-in replacement for msvcrt.dll, apparently.
    
    Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

Diff:
---
 winsup/cygwin/syscalls.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/winsup/cygwin/syscalls.cc b/winsup/cygwin/syscalls.cc
index 16780a12e..11af079cb 100644
--- a/winsup/cygwin/syscalls.cc
+++ b/winsup/cygwin/syscalls.cc
@@ -5217,6 +5217,7 @@ pipe_worker (int filedes[2], unsigned int psize, int mode)
   return res;
 }
 
+/* MS compatible version of pipe.  Hopefully nobody is using it... */
 extern "C" int
 _pipe (int filedes[2], unsigned int psize, int mode)
 {