[TensorExpr] scalar factorization of Div (#36154)
Summary:
Add support for the TensorExpr IR Simplifier to factorize common terms on either side of a Div node. e.g. `(8 * x) / (4 * y) => (2 * x) / y`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36154
Differential Revision: D20910580
Pulled By: nickgg
fbshipit-source-id: ee071d93bc4711b1e710be312de599d18ab506f3
