[JIT] fix torch.tensor jit dtype (#36587)
Summary:
Previously we were always creating a double tensor from `torch.tensor(1.)`, whereas python eager uses the current default dtype. Fix for https://github.com/pytorch/pytorch/issues/36369
Pull Request resolved: https://github.com/pytorch/pytorch/pull/36587
Differential Revision: D21043617
Pulled By: eellison
fbshipit-source-id: 38da303594f52e06941d86b6e57c4a06e7d36938
