getitem batching rule failure

repro:
```
import torch
import torch.autograd.forward_ad as fwAD
from functorch import make_fx, vmap

x = torch.arange(3 * 5 * 5 * 5).view(3, 5, 5, 5)

def select(x):
    return x[(0, 0), :, (1, 1)]

y = vmap(select)(x)
print(y.shape)

print(select(x[0]).shape)

y = make_fx(vmap(select))(x)
print(y.code)
```
gonna xfail for now