Consider bumping stack size in ruby_qsort
At the moment the maximum size of the stack is 32. The comment implies this should be enough for arrays with up to 2**32 elements, but it's possible to create larger arrays on some big systems.
I was not able to trigger a bug with: ([0, 1] * (2**32 + 10000)).sort! so it may actually never be a problem in practice, but it seems unsafe.