Rewrite Scripting.ActivateScript
Rewrite Scripting.ActivateScript

`ActivateScript` has now been rewritten to match the ActivateLoop in
`Scripting_ProcessRoomStartupScript`.

This slightly improves the speed of `ActivateScript` (582 vs 591 average
cycles in the Mesen-S Performance Profiler).

undisbeliever/untech-engine