patch 8.2.4050: Vim9: need to prefix every item in an autoload script

Problem:    Vim9: need to prefix every item in an autoload script.
Solution:   First step in supporting "vim9script autoload" and "import
            autoload".
diff --git a/src/eval.c b/src/eval.c
index 390bb58..7a23876 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -886,7 +886,9 @@
 
     if (*p == '.' && in_vim9script())
     {
-	imported_T *import = find_imported(lp->ll_name, p - lp->ll_name, NULL);
+	imported_T *import = find_imported(lp->ll_name, p - lp->ll_name,
+								   TRUE, NULL);
+
 	if (import != NULL)
 	{
 	    ufunc_T *ufunc;