`rt::Allocation` doesn't alert on double-free

[abonander]

Looking through the implementation of loom::alloc::Track and rt::Allocation, I was surprised to see that it apparently doesn't alert on a double-free:

loom/src/rt/alloc.rs

Lines 68 to 80 in dbf32b0

	impl Drop for Allocation {
	#[track_caller]
	fn drop(&mut self) {
	let location = location!();
	rt::execution(|execution| {
	let state = self.state.get_mut(&mut execution.objects);
	trace!(state = ?self.state, drop.location = %location, "Allocation::drop");
	state.is_dropped = true;
	});
	}
	}

It looks like if a user is directly calling dealloc(), that would catch a double-free, but with a potentially unhelpful panic message:

loom/src/rt/alloc.rs

Line 45 in dbf32b0

None => panic!("pointer not tracked"),

I'm wondering if there's a reason why checking for double-frees was omitted, or if this is just an oversight. It seems like a whole class of possible bugs is being overlooked here.