Advice requested for fixing issue 17914

[Brian Schott]

On Tuesday, 24 October 2017 at 21:49:10 UTC, qznc wrote:
> My question wrt to the bug: Why is munmap/freeStack called in 
> the destructor? Could be done right after termination?

I've been reading the Fiber code and (so far) that seems seems to 
be reasonable. Can anybody think of a reason that this would be a 
bad idea? I'd rather not create a pull request for a design 
that's not going to work because of a detail I've overlooked.