ENH: Workaround -1 reduce identity for unsigned integers
ENH: Workaround -1 reduce identity for unsigned integers

This is a temporary solution until such a time where we can have
loop specific identities which can handle this more gracefully.

numpy/numpy,numpy/numpy,numpy/numpy,mattip/numpy,mattip/numpy,charris/numpy,charris/numpy,numpy/numpy,endolith/numpy,endolith/numpy,charris/numpy,charris/numpy,endolith/numpy,mattip/numpy,mattip/numpy,endolith/numpy