There are platforms it isn't implemented on (and currently can't be
implemented on!), and there's currently no way for an app to know this.
This shouldn't break ABI on apps that moved to a revision between 2.0.3 and
2.0.4.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().