patch 9.1.0391: Vim9: could improve testing

Problem:  Vim9: could improve testing
          (Ernie Rael)
Solution: Support defcompile for test_override() to
          improve testing (Yegappan Lakshmanan)

fixes: #14553
closes: #14712

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/testing.txt b/runtime/doc/testing.txt
index 9b9f60b..d0f1d46 100644
--- a/runtime/doc/testing.txt
+++ b/runtime/doc/testing.txt
@@ -1,4 +1,4 @@
-*testing.txt*	For Vim version 9.1.  Last change: 2024 Apr 07
+*testing.txt*	For Vim version 9.1.  Last change: 2024 May 03
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -369,6 +369,9 @@
 		autoload     `import autoload` will load the script right
 			     away, not postponed until an item is used
 		char_avail   disable the char_avail() function
+		defcompile   all the |:def| functions in a sourced script are
+			     compiled when defined.  This is similar to using
+			     the |:defcompile| command in a script.
 		nfa_fail     makes the NFA regexp engine fail to force a
 			     fallback to the old engine
 		no_query_mouse  do not query the mouse position for "dec"