make --dump-ir also dump sass (#2460)
Summary:
Triton has a `get_sass` utility that disassembles the cubin and gets the sass - in this PR, we try to use `get_sass` when running with `--dump-ir`, if we can find a cubin file.
Pull Request resolved: https://github.com/pytorch/benchmark/pull/2460
Reviewed By: xuzhao9
Differential Revision: D62925358
Pulled By: davidberard98
fbshipit-source-id: 7aa1e66c43222b776c949ced3fdcabcee30fbb21
