sdl2-compat: SDL_config.h: Assume that Unix platforms define __unix__

From fd4b4153f7efd661cd0b7904f7b8e2eeea07a224 Mon Sep 17 00:00:00 2001
From: Simon McVittie <[EMAIL REDACTED]>
Date: Tue, 4 Feb 2025 19:57:25 +0000
Subject: [PATCH] SDL_config.h: Assume that Unix platforms define __unix__

This is believed to be a predefined macro on all reasonable Unix
platforms in practice (it's certainly predefined on GNU/Linux).
We can add some `|| defined(__myplatform__)` as necessary, but
this way is more readable than listing every Unix we know about
individually.

https://sourceforge.net/p/predef/wiki/OperatingSystems/ notes that
"the xlC or the DEC C/C++ compiler" don't define these, but that doesn't
seem likely to have any practical impact on us.

Signed-off-by: Simon McVittie <smcv@collabora.com>
---
 include/SDL2/SDL_config.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/SDL2/SDL_config.h b/include/SDL2/SDL_config.h
index 698018a..2a1f4bb 100644
--- a/include/SDL2/SDL_config.h
+++ b/include/SDL2/SDL_config.h
@@ -47,7 +47,7 @@
 #include "SDL_config_emscripten.h"
 #elif defined(__NGAGE__)
 #include "SDL_config_ngage.h"
-#elif defined (__LINUX__) || defined(__FREEBSD__) || defined(__NETBSD__) || defined(__OPENBSD__) || defined(__SOLARIS__)
+#elif defined(__unix__)
 #include "SDL_config_unix.h"
 #else
 /* This is a minimal configuration just to get SDL running on new platforms. */