Why is SDL_HasMMXExt missing in SDL2

Question

In SDL 1.2, there is SDL_HasMMXExt. See here. The full source of the file can be seen here.

In SDL 2, that function is missing. Why? The full source of SDL2 of the same file can be seen here.

Relevant code of SDL 1.2 is this:

static __inline__ int CPU_haveMMX(void)
{
      if ( CPU_haveCPUID() ) {
            return (CPU_getCPUIDFeatures() & 0x00800000);
      }
      return 0;
}

static __inline__ int CPU_haveMMXExt(void)
{
      if ( CPU_haveCPUID() ) {
            return (CPU_getCPUIDFeaturesExt() & 0x00400000);
      }
      return 0;
}

CPU_getCPUIDFeaturesExt is also missing in SDL2. Why was it removed?