Missing visual effect from ice traps in most chests

[fenhl]

If an ice trap is in a chest which is also an ice trap in vanilla, you can clearly see a visual frost effect. If an ice trap is in a different chest, this effect is missing.

[GSKirox]

So i was looking at the chest decomp for an unrelated reason, and i noticed something related to this : https://github.com/zeldaret/oot/blob/master/src/code/z_effect_soft_sprite_old_init.c#L1166 says it needs OBJECT_FZ to be loaded on the scene, which is related to the Freezards enemies.

So i did a quick test and indeed, if you put an ice trap in a chest in a room where there are Freezards like Water Trial for example, the effect does work ! So maybe a way to make this work would be to somehow load this object on the scene when an ice trap is in the chest.

[fenhl]

The PR fixing this was reverted, see #2210 for the reason. Any future attempt at fixing this should ensure that crash is avoided. @rrealmuto has mentioned that there is such a fix on the boulder shuffle branch.

[flagrama]

@GSKirox looking at your old PR and the object_index_or_spawn function you used, it seems to call a function from the game it believes is called something like z64_ObjectSpawn. However, no function for an actor to spawn an object seems to exist in the game. There is a function used during scene setup that is probably the one being called. The problem is it makes that object and every one loaded before it persistent through room changes. This persistence is what I think must have been causing the crashes. AFAICT from my own experiments, reimplementing that function and just leaving the line that re-sets the number of persistent entries out of it will load objects on the fly without making them persistent.