ENH, SIMD: dispatch argmax/armin for vx vxe
ENH, SIMD: dispatch argmax/armin for vx vxe

mattip/numpy,mhvk/numpy,endolith/numpy,mattip/numpy,rgommers/numpy,pdebuyl/numpy,pdebuyl/numpy,endolith/numpy,mattip/numpy,numpy/numpy,anntzer/numpy,pdebuyl/numpy,pdebuyl/numpy,numpy/numpy,anntzer/numpy,rgommers/numpy,rgommers/numpy,mhvk/numpy,anntzer/numpy,endolith/numpy,endolith/numpy,charris/numpy,mhvk/numpy,numpy/numpy,charris/numpy,rgommers/numpy,mattip/numpy,numpy/numpy,charris/numpy,mhvk/numpy,anntzer/numpy,mhvk/numpy,charris/numpy