Allow up to 12 enemy types in a room. Use this patch if you are adding more than 4 entries to the enemy type list. This doesn't invent new palette lines on the SNES, so enemies will have to double up on the same palette line. This also doesn't add more VRAM, so it's really only realistic to have many small enemy types and not large ones.

Uses Free WRAM at $7EF4A0-$7EF4CF and the last enemy entry (temporarily during room load).