[TensorExpr] Remove unused EvalConstExpr function (#45180)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/45180
Test Plan: build
Reviewed By: ezyang
Differential Revision: D23877151
Pulled By: asuhan
fbshipit-source-id: a5d4d211c1dc85e6f7045330606163a933b9474e
