patch 9.0.1915: r_CTRL-C works differently in visual mode

Problem:  r_CTRL-C works differently in visual mode
Solution: Make r_CTRL-C behave consistent in visual mode
          in terminal and Windows GUI

in visual mode, r CTRL-C behaves strange in Unix like environments. It
seems to end visual mode, but still is waiting for few more chars,
however it never seems to replace it by any characters and eventually
just returns back into normal mode.

In contrast in Windows GUI mode, r_CTRL-C replaces in the selected area
all characters by a literal CTRL-C.

Not sure why it behaves like this. It seems in the Windows GUI, got_int
is not set and therefore behaves as if any other normal character has
been pressed.

So remove the special casing of what happens when got_int is set and
make it always behave like in Windows GUI mode. Add a test to verify it
always behaves like replacing in the selected area each selected
character by a literal CTRL-C.

closes: #13091
closes: #13112

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/runtime/doc/visual.txt b/runtime/doc/visual.txt
index 540d5c5..616e773 100644
--- a/runtime/doc/visual.txt
+++ b/runtime/doc/visual.txt
@@ -1,4 +1,4 @@
-*visual.txt*    For Vim version 9.0.  Last change: 2022 Dec 04
+*visual.txt*    For Vim version 9.0.  Last change: 2023 Sep 19
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -183,6 +183,8 @@
 CTRL-C			In Visual mode: Stop Visual mode.  When insert mode is
 			pending (the mode message shows
 			"-- (insert) VISUAL --"), it is also stopped.
+			On MS-Windows, you may need to press CTRL-Break 
+			|dos-CTRL-Break|.
 
 ==============================================================================
 3. Changing the Visual area				*visual-change*