[jit] Fix jit not round to even if const is folded (#40897)
Summary:
Fixed https://github.com/pytorch/pytorch/issues/40771
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40897
Reviewed By: Krovatkin
Differential Revision: D22543261
Pulled By: gmagogsfm
fbshipit-source-id: 0bd4b1d910a42d5aa87e120c81acfdfb7ca895fa