[newlib-cygwin/main] Cygwin: Update documentation for cygwin_stackdump

[Jon Turney]

https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=07cccc74a5da0da5bb664411e4cf76b3d35bc09d

commit 07cccc74a5da0da5bb664411e4cf76b3d35bc09d
Author: Jon Turney <jon.turney@dronecode.org.uk>
Date:   Thu Jan 11 17:37:03 2024 +0000

    Cygwin: Update documentation for cygwin_stackdump

Diff:
---
 winsup/doc/misc-funcs.xml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/winsup/doc/misc-funcs.xml b/winsup/doc/misc-funcs.xml
index 7463942e6..2503dd3b7 100644
--- a/winsup/doc/misc-funcs.xml
+++ b/winsup/doc/misc-funcs.xml
@@ -106,6 +106,10 @@ enum.  The second is an optional pointer.</para>
   <refsect1 id="func-cygwin-stackdump-desc">
     <title>Description</title>
 <para> Outputs a stackdump to stderr from the called location.
+</para>
+<para> Note: This function only has an effect the first time it is called by a process.
+</para>
+<para> Note: This function is deprecated.
 </para>
   </refsect1>
 </refentry>