Fix default dtype in shape analysis (#18968)
Summary:
Fix for https://github.com/pytorch/pytorch/issues/18823
Previously we were setting the dtype to Float when in torchscript the default is double. When the problem in https://github.com/pytorch/pytorch/issues/17662 gets landed, we will have to reevalute (and this test will fail).
We should still be consistent in shape_analysis in the meantime.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/18968
Differential Revision: D14837939
Pulled By: eellison
fbshipit-source-id: 32383b55c14bdc7753e26dec33c39ab10124c255
