Update linspace and bump version nuymber to 8 (#71486)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71486
This PR adds upgraders for linspace and linspace.out as the optional step size will be deprecated soon. Old models will be using steps size of 100 when nothing is provided.
Test Plan: buck-out/gen/caffe2/test/jit#binary.par -r TestUpgraders.test_aten_linspace
Reviewed By: cccclai, mruberry
Differential Revision: D33654308
fbshipit-source-id: 0e0138091da0b11d4f49156eeb6bcd7e46102a5b
(cherry picked from commit 931ae4af3200b37d1cebcb7f30e8ba880c1305ec)
