Removing oGC from castle from CHILD_FORBIDDEN generates unbeatable seeds

[fenhl]

The following plando shouldn't generate, since there is no child access to the windmill, which in ALR is required for the Drain Well event:

{
    "settings": {
        "shuffle_interior_entrances": "all",
        "shuffle_dungeon_entrances": "all",
        "shuffle_overworld_entrances": true,
        "mix_entrance_pools": [
            "Interior",
            "Dungeon",
            "Overworld"
        ]
    },
    "entrances": {
        "Ganons Castle Ledge -> Ganons Castle Lobby": {
            "region": "ToT Entrance",
            "from": "Market"
        },
        "ToT Entrance -> Temple of Time": "Kak Windmill"
    }
}

The plando correctly doesn't generate on the current version of my branch since e5ea217b, which added the entrance back to CHILD_FORBIDDEN, but ideally it shouldn't be forbidden since the entrance has been moved for child and won't cause problems with the trade sequence anymore.

[fenhl]

Turns out this is intended behavior. All Locations Reachable specifically doesn't check for reachability of Drop and Event locations. In the seed where this issue was found, the well had a small fairy fountain. Draining the well is an event, and fairies are drops, so everything is fine. Plandoing Mido's house to be inside the well results in the error “Cannot connect Kakariko Village -> Bottom of the Well To KF Midos House in world 1 (Reason: KF Midos Top Left Chest is unreachable)”. I've reverted e5ea217 now.