[TensorExpr] Add dtype to class Buf. (#36611)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36611
Currently Buf represents underlying storage but it didn't have dtype.
That resulted in specifying dtypes in different places and there was no
mechanism to enforce its consistency: e.g. one could've created a kFloat
expression and use a kInt buffer to store its result. Now we're
centralizing where the logic regarding the storage is located and we can
start enforcing semantics rules.
Follow-ups: we can merge Buffer and BufHandle classes as the former is
now a mere wrapper over the latter.
Test Plan: Imported from OSS
Differential Revision: D21027356
Pulled By: ZolotukhinM
fbshipit-source-id: c06aa2c4077fdcde3bb4ca622d324aece79b5a9c
Author
Mikhail Zolotukhin
