patch 9.1.0059: No event triggered before creating a window

Problem:  No event is triggered before creating a window.
          (Sergey Vlasov)
Solution: Add the WinNewPre event (Sergey Vlasov)

fixes: #10635
closes: #12761

Signed-off-by: Sergey Vlasov <sergey@vlasov.me>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim.h b/src/vim.h
index 0f52ba2..fe23958 100644
--- a/src/vim.h
+++ b/src/vim.h
@@ -1435,7 +1435,8 @@
     EVENT_VIMRESIZED,		// after Vim window was resized
     EVENT_WINENTER,		// after entering a window
     EVENT_WINLEAVE,		// before leaving a window
-    EVENT_WINNEW,		// when entering a new window
+    EVENT_WINNEWPRE,		// before creating a new window
+    EVENT_WINNEW,		// after creating a new window
     EVENT_WINCLOSED,		// after closing a window
     EVENT_VIMSUSPEND,		// before Vim is suspended
     EVENT_VIMRESUME,		// after Vim is resumed