bug#73559: [PATCH] fix NS build focus-in event processing

[Daniel Colascione <dancol@dancol.org>]

In Emacs NS build, frames don't respond to focus-in events right away.
Instead, they store the focus-in event and process it (and other queued
events) whenever some other event happens to occur on that frame.

This patch kicks the NS event loop immediately when a focus-in event
happens, allowing Emacs to respond to focus-in events without some other
event triggering the processing.

commit c6d98bfc2a098b57fa9631978224ead2668d3a88
Author: Daniel Colascione <dancol@dancol.org>
Date:   Wed Aug 21 19:48:05 2024 -0700

    process events on focus in

diff --git a/src/nsterm.m b/src/nsterm.m
index 8c405738467..f68a22d9fbc 100644
--- a/src/nsterm.m
+++ b/src/nsterm.m
@@ -7973,6 +7973,7 @@ - (void)windowDidBecomeKey      /* for direct calls */
   event.kind = FOCUS_IN_EVENT;
   XSETFRAME (event.frame_or_window, emacsframe);
   kbd_buffer_store_event (&event);
+  ns_send_appdefined (-1);  // Kick main loop
 }