* Skeleton methods for IndexAdd/ScatterAdd.
* Add a Map2InPlace trait.
* Add the glue code for the index-add/scatter-add kernels.
* Tweak the file name: embeddings -> indexing.
* Add the cuda kernel for indexadd.
* And add the scatter-add kernels.
* Boilerplate code for conv1d.
* Boilerplate code for conv1d.
* More boilerplate for conv1d.
* Conv1d work.
* Get the conv1d cuda kernel to work.
* Conv1d support when no batch dim.
