Normalise indices for setitem

Effort to test thoroughly, so trusting in NumPy's own tests down-the-line

Author: honno

torch_np/_ndarray.py

@@ -297,6 +297,8 @@ def __getitem__(self, index):
         return ndarray._from_tensor_and_base(self._tensor.__getitem__(index), self)
 
     def __setitem__(self, index, value):
+        index = _helpers.to_tensors(index)
+        index = ndarray._upcast_int_indices(index)
         value = asarray(value).get()
         return self._tensor.__setitem__(index, value)