Require CUDA if CHAINERX_BUILD_CUDA is set
Require CUDA if CHAINERX_BUILD_CUDA is set

hvy/chainer,okuta/chainer,okuta/chainer,okuta/chainer,chainer/chainer,niboshi/chainer,niboshi/chainer,pfnet/chainer,niboshi/chainer,chainer/chainer,wkentaro/chainer,hvy/chainer,chainer/chainer,wkentaro/chainer,wkentaro/chainer,hvy/chainer,okuta/chainer,niboshi/chainer,chainer/chainer,hvy/chainer,wkentaro/chainer