[TensorExpr] add more detail to malformed_input exceptions (#35891)
Summary:
Add an explanation string to malformed_input exceptions thrown inside jit/tensorexpr to aid in debugging issues.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/35891
Differential Revision: D20822306
Pulled By: nickgg
fbshipit-source-id: ce153a05218f2a4da5ecf5f1a5dc439070c96e55
