[PATCH] ui/sdl2: use correct key names in win title on mac

[Adrian Wowk <dev@adrianwowk.com>]

Previously, when using the SDL2 UI on MacOS, the title bar uses incorrect
key names (such as Ctrl and Alt instead of the standard MacOS key symbols
like ⌃ and ⌥). This commit changes sdl_update_caption in ui/sdl2.c to
use the correct symbols when compiling for MacOS (CONFIG_DARWIN is
defined).

Unfortunately, standard Mac keyboards do not include a "Right-Ctrl" key,
so in the case that the SDL grab mode is set to HOT_KEY_MOD_RCTRL, the
default text is still used.

Signed-off-by: Adrian Wowk <dev@adrianwowk.com>
---
Hi! I created this patch after having to compile QEMU from source with the SDL UI enabled to avoid an unrelated bug in the Cocoa UI. I noticed that the title of the window was not correct so I added a quick fix. I have tested this change on MacOS Sonoma (Version 14.1), and it works as expected. I did my best to ensure correctness, but this is my first time contrbuting to QEMU (and also my first time sending git patches over email), so if there is anything I can do better then please let me know. Thank You!

 ui/sdl2.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/ui/sdl2.c b/ui/sdl2.c
index fbfdb64e90..4971963f00 100644
--- a/ui/sdl2.c
+++ b/ui/sdl2.c
@@ -172,11 +172,19 @@ static void sdl_update_caption(struct sdl2_console *scon)
         status = " [Stopped]";
     } else if (gui_grab) {
         if (alt_grab) {
+#ifdef CONFIG_DARWIN
+            status = " - Press ⌃⌥⇧G to exit grab";
+#else
             status = " - Press Ctrl-Alt-Shift-G to exit grab";
+#endif
         } else if (ctrl_grab) {
             status = " - Press Right-Ctrl-G to exit grab";
         } else {
+#ifdef CONFIG_DARWIN
+            status = " - Press ⌃⌥G to exit grab";
+#else
             status = " - Press Ctrl-Alt-G to exit grab";
+#endif
         }
     }
 
-- 
2.39.3 (Apple Git-145)