Run:
```
isort ./python
autopep8 -i --ignore E501,E701,E731 $(find ./python/ -name '*.py')
```
with an `.isort.cfg` and then clean up a few warts. This PR should be a no-op; the idea is that this is all boring whitespace changes, and any config file changes will be in a different change to make it easier to review.
A forthcoming PR will update the RNG to use these types.
Also:
- Add tests for the `//`, `<<`, and `>>` operators.
- Change `TensorWrapper` to unwrap objects when the resulting object would be simpler.
- Clean up `throw_unreachable`, since it was triggering compiler warnings.
Since numpy supports unsigned integers, and pytorch doesn't, this will make it easier to test unsigned integer support.
This adds an explicit requirement for numpy in tests, but we already required scipy, so it was already an implicit dependency.
- `BF16TyID` was missing a repr implementation.
- Throw a better exception on impossible casts.
- Add a few assertions. Tested with a debug build.
- Add `pointer_dtype.__str__` to aid kernel debugging.
- Promote 16-bit floating-point `/` and `%` to 32-bit; we have to anyway.
- Do not force result of integer binary operations to be the LHS type. There used to be a bug in pytorch that did this, which Triton matched, but that bug is fixed now.
- When testing signed integer operations, use random numbers from the full range of the type.
- Add an optional `seed` argument to `triton.testing.random` so binary operations are not tested with both sides equal when the LHS and RHS have the same type.
- Fix a bad `CompilationError` invocation.
- Fix a warning suppression that causes tests to fail if you run them with `-W error` on python 3.8.
- Fix some whitespace.
- Make an undeclared dependency on `pytest` explicit.
- Fix deprecated `description-file` use.
- `#ifdef` out a deprecated `PyEval_InitThreads` call.
- Use a slightly different numpy invocation in `test_random.py` to quiet down overflow warnings in tests.
- Fix a deprecated cast in `test_core.py`.
- Suppress a warning about `visit_Constant` in Python 3.9+; we can't migrate yet because it'd break Python 3.6 and 3.7.
- Use chained exceptions for `CompilationError` rather than rolling our own; it makes the error messages nicer.
- Add a `__str__` for `tl.dtype` to make debugging kernels easier; it lets you `print` a dtype to see what type was inferred.
- Fix a few bad escapes.
