Do we reset rsp correctly?

[ltratt]

This might be me being very, very stupid, but in patch_frame_allocation we retrospectively make sure rsp is given enough space for all the spills the trace needs:

let stack_size = self.ra.align_stack(SYSV_CALL_STACK_ALIGN) - self.sp_offset;
match i32::try_from(stack_size) {
    Ok(asp) => {
	let mut patchup = self.asm.alter_uncommitted();
	patchup.goto(asm_off);
	dynasm!(patchup ; sub rsp, DWORD asp);

For example for big_loop this inserts:

sub rsp, 0x30

as the very first instruction of the trace.

However, when a guard fails we seem to pass rsp in without subtracting that offset. Nor, as far as I can see, is that stack offset information available to __yk_deopt. Does this mean we gradually end up with the wrong rsp as we fail from guards?