UB2 now signs and notarizes, upgraded to SDL 2.0.16

Also works on Apple Silicon. Specific signing values are in a non-committed file, and the ub2 script only notarizes if a "notarize" flag is passed in on the command line.

NOTE: the SDL dylib currently only has x86_64 and arm64, will need extra work to graft those back in and keep the Notary service happy.

code/SDL2/include/SDL_config_iphoneos.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
@@ -112,8 +112,12 @@
 #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
@@ -166,10 +170,12 @@
 #define SDL_VIDEO_DRIVER_DUMMY  1
 
 /* Enable OpenGL ES */
+#if !TARGET_OS_MACCATALYST
 #define SDL_VIDEO_OPENGL_ES2 1
 #define SDL_VIDEO_OPENGL_ES 1
 #define SDL_VIDEO_RENDER_OGL_ES 1
 #define SDL_VIDEO_RENDER_OGL_ES2    1
+#endif
 
 /* Metal supported on 64-bit devices running iOS 8.0 and tvOS 9.0 and newer
    Also supported in simulator from iOS 13.0 and tvOS 13.0