Minor change to enable using Chainer with PyPy
Minor change to enable using Chainer with PyPy

hvy/chainer,jnishi/chainer,niboshi/chainer,ktnyt/chainer,ktnyt/chainer,wkentaro/chainer,keisuke-umezawa/chainer,niboshi/chainer,anaruse/chainer,wkentaro/chainer,ktnyt/chainer,wkentaro/chainer,okuta/chainer,okuta/chainer,chainer/chainer,jnishi/chainer,chainer/chainer,okuta/chainer,rezoo/chainer,wkentaro/chainer,ktnyt/chainer,keisuke-umezawa/chainer,jnishi/chainer,ronekko/chainer,chainer/chainer,hvy/chainer,hvy/chainer,okuta/chainer,chainer/chainer,aonotas/chainer,keisuke-umezawa/chainer,niboshi/chainer,niboshi/chainer,jnishi/chainer,tkerola/chainer,keisuke-umezawa/chainer,pfnet/chainer,hvy/chainer