Having max-memory savestates saved prevents overriding a state

[Nambo0]

Savestates seem to allocate new memory before freeing up old memory, meaning if u have max savestates on a level before crashing, u can't replace one of ur old savestates unless u manually clear the state with a bind and then make a new one

It wont crash or anything, but it fails to override savestates at max capacity essentially

[ComplexPlane]

We can guarantee there's enough space if the current slot's savestate is at least as large as the incoming state, but it's technically possible there's enough space even if the current state is too small due to heap fragmentation. We could be less conservative if we e.g. used a pooled block allocator for savestates instead of a heap - savestates are the only allocations we use a heap for anyway.

... but also people would probably bump into savestate size limitations much less frequently if we further optimized savestates.