patch 9.1.1084: Unable to persistently ignore events in a window and its buffers

Problem:  Unable to persistently ignore events in a window and its buffers.
Solution: Add 'eventignorewin' option to ignore events in a window and buffer
          (Luuk van Baal)

Add the window-local 'eventignorewin' option that is analogous to
'eventignore', but applies to a certain window and its buffers. Identify
events that should be allowed in 'eventignorewin', adapt "auto_event"
and "event_tab" to encode this information. Window context is not passed
onto apply_autocmds_group(), and when to ignore an event is a bit
ambiguous when "buf" is not "curbuf", rather than a large refactor, only
ignore an event when all windows into "buf" are ignoring the event.

closes: #16530

Signed-off-by: Luuk van Baal <luukvbaal@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/testdir/gen_opt_test.vim b/src/testdir/gen_opt_test.vim
index 2dfb070..1918bda 100644
--- a/src/testdir/gen_opt_test.vim
+++ b/src/testdir/gen_opt_test.vim
@@ -189,6 +189,8 @@
       \ 'encoding': [['latin1'], ['xxx', '']],
       \ 'eventignore': [['', 'WinEnter', 'WinLeave,winenter', 'all,WinEnter'],
       \		['xxx']],
+      \ 'eventignorewin': [['', 'WinEnter', 'WinLeave,winenter', 'all,WinEnter'],
+      \		['xxx', 'WinNew']],
       \ 'fileencoding': [['', 'latin1', 'xxx'], []],
       \ 'fileformat': [['', 'dos', 'unix', 'mac'], ['xxx']],
       \ 'fileformats': [['', 'dos', 'dos,unix'], ['xxx']],