sdl2-compat: SDL_config_unix: Assume that Unix platforms build SDL with libc

From 6747750200286b6416b581278c314c626e9a473a Mon Sep 17 00:00:00 2001
From: Simon McVittie <[EMAIL REDACTED]>
Date: Wed, 5 Feb 2025 14:10:35 +0000
Subject: [PATCH] SDL_config_unix: Assume that Unix platforms build SDL with
 libc

On platforms like Windows it's reasonable to rely on a platform-specific
interface like Win32 for I/O, but on Unix, libc stdio is more likely to
be the only thing there is.

Signed-off-by: Simon McVittie <smcv@collabora.com>
---
 include/SDL2/SDL_config_unix.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/include/SDL2/SDL_config_unix.h b/include/SDL2/SDL_config_unix.h
index 2f2aac1..c417bee 100644
--- a/include/SDL2/SDL_config_unix.h
+++ b/include/SDL2/SDL_config_unix.h
@@ -37,6 +37,9 @@
 #define HAVE_GCC_ATOMICS 1
 #endif
 
+/* Assume that on Unix, it's conventional to build with a libc dependency */
+#define HAVE_LIBC 1
+
 /* Assume that any reasonable Unix platform has Standard C headers */
 #define STDC_HEADERS 1
 #define HAVE_CTYPE_H 1