Update SDL to 2.0.18

libs/SDL2/include/SDL_config_macosx.h

@@ -1,6 +1,6 @@
 /*
   Simple DirectMedia Layer
-  Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>
+  Copyright (C) 1997-2021 Sam Lantinga <slouken@libsdl.org>
 
   This software is provided 'as-is', without any express or implied
   warranty.  In no event will the authors be held liable for any damages
@@ -52,6 +52,7 @@
 #define HAVE_LIBUNWIND_H    1
 
 /* C library functions */
+#define HAVE_DLOPEN 1
 #define HAVE_MALLOC 1
 #define HAVE_CALLOC 1
 #define HAVE_REALLOC    1
@@ -115,8 +116,12 @@
 #define HAVE_LOGF   1
 #define HAVE_LOG10  1
 #define HAVE_LOG10F 1
+#define HAVE_LROUND 1
+#define HAVE_LROUNDF 1
 #define HAVE_POW    1
 #define HAVE_POWF   1
+#define HAVE_ROUND 1
+#define HAVE_ROUNDF 1
 #define HAVE_SCALBN 1
 #define HAVE_SCALBNF    1
 #define HAVE_SIN    1
@@ -133,6 +138,16 @@
 #define HAVE_SYSCONF    1
 #define HAVE_SYSCTLBYNAME 1
 
+#if defined(__has_include) && (defined(__i386__) || defined(__x86_64))
+# if __has_include(<immintrin.h>)
+#   define HAVE_IMMINTRIN_H 1
+# endif
+#endif
+
+#if (MAC_OS_X_VERSION_MAX_ALLOWED >= 1070)
+#define HAVE_O_CLOEXEC 1
+#endif
+
 #define HAVE_GCC_ATOMICS 1
 
 /* Enable various audio drivers */
@@ -191,7 +206,6 @@
  */
 #define SDL_VIDEO_DRIVER_X11_XINPUT2 1
 #define SDL_VIDEO_DRIVER_X11_SUPPORTS_GENERIC_EVENTS 1
-#define SDL_VIDEO_DRIVER_X11_CONST_PARAM_XEXTADDDISPLAY 1
 #endif
 
 #ifndef SDL_VIDEO_RENDER_OGL