patch 9.1.0500: cannot switch buffer in a popup

Problem:  cannot switch buffer in a popup
          (Yggdroot)
Solution: add popup_setbuf() function

fixes: #15006
closes: #15026

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt
index 5b5bded..86dfe6d 100644
--- a/runtime/doc/version9.txt
+++ b/runtime/doc/version9.txt
@@ -1,4 +1,4 @@
-*version9.txt*  For Vim version 9.1.  Last change: 2024 Jun 17
+*version9.txt*  For Vim version 9.1.  Last change: 2024 Jun 18
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -41586,6 +41586,7 @@
 |getregionpos()|	get a list of positions for a region
 |matchbufline()|	all the matches of a pattern in a buffer
 |matchstrlist()|	all the matches of a pattern in a List of strings
+|popup_setbuf()|	switch to a different buffer in a popup
 
 
 Autocommands: ~