error: SDL's allocators now call SDL_OutOfMemory on error.

This means the allocator's caller doesn't need to use SDL_OutOfMemory directly
if the allocation fails.

This applies to the usual allocators: SDL_malloc, SDL_calloc, SDL_realloc
(all of these regardless of if the app supplied a custom allocator or we're
using system malloc() or an internal copy of dlmalloc under the hood),
SDL_aligned_alloc, SDL_small_alloc, SDL_strdup, SDL_asprintf, SDL_wcsdup...
probably others. If it returns something you can pass to SDL_free, it should
work.

The caller might still need to use SDL_OutOfMemory if something that wasn't
SDL allocated the memory: operator new in C++ code, Objective-C's alloc
message, win32 GlobalAlloc, etc.

Fixes #8642.

src/thread/n3ds/SDL_sysmutex.c

@@ -31,8 +31,6 @@ SDL_Mutex *SDL_CreateMutex(void)
     SDL_Mutex *mutex = (SDL_Mutex *)SDL_malloc(sizeof(*mutex));
     if (mutex) {
         RecursiveLock_Init(&mutex->lock);
-    } else {
-        SDL_OutOfMemory();
     }
     return mutex;
 }