// depth, the stack check test fails.
	//
	// The call to morestack in every splittable function ensures
	// that there are at least StackLimit bytes available below SP
	// when morestack returns.
	limit := objabi.StackNosplit(*flagRace) - sc.callSize
	if buildcfg.GOARCH == "arm64" {
		// Need an extra 8 bytes below SP to save FP.
		limit -= 8
	}

	// Compute stack heights without any back-tracking information.

	f = findfunc(abi.FuncPCABIInternal(asyncPreempt2))
	total += funcMaxSPDelta(f)
	// Add some overhead for return PCs, etc.
	asyncPreemptStack = uintptr(total) + 8*goarch.PtrSize
	if asyncPreemptStack > stackNosplit {
		// We need more than the nosplit limit. This isn't
		// unsafe, but it may limit asynchronous preemption.
		//
		// This may be a problem if we start using more