* add dtypes.index
* cast shape, stride and mask to dtypes.index in view.create
* move pm_lower_index_dtype to ops
* DEFINE_VAR is dtype.index by default
* merge var_val_using_str
* remove int from commutative
* fix test_rewrite_map
* change that to dtypes.index
* change some int to index
* shorten those
* remove old cast in renderer
* cleanup
* change that back
* add comment
* delete comment
* just delete those
* view doesnt have to cast anymore
* adjust comment