patch 9.1.0211: page-wise scrolling does not support smooth-scrolling

Problem:  Page-wise scrolling with Ctrl-F/Ctrl-B implements
          it's own logic to change the topline and cursor.
          In doing so, skipcol is not handled properly for
          'smoothscroll', and virtual lines.
Solution: Re-use the logic from Ctrl-E/Ctrl-Y while staying
          backward compatible as much as possible.

closes: #14268

Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/version9.txt b/runtime/doc/version9.txt
index b94d157..82482a7 100644
--- a/runtime/doc/version9.txt
+++ b/runtime/doc/version9.txt
@@ -41554,6 +41554,8 @@
 Changed						*changed-9.2*
 -------
 
+- use 'smoothscroll' logic for CTRL-F and CTRL-B for pagewise scrolling
+
 Added						*added-9.2*
 -----