Remove tools/setup_helpers/dist_check.py (#25879)
Summary:
What dist_check.py does is largely merely determining whether we should
use set "USE_IBVERBS" to ON or OFF when the user sets "USE_GLOO_IBVERBS"
to ON. But this is unnecessary, because this complicated determination
will always be overrided by gloo:
https://github.com/facebookincubator/gloo/blob/2101e02ceabd9f1b0bb354f6ea705cefe83558b2/cmake/Dependencies.cmake#L19-L28
Since dist_check.py becomes irrelevant, this commit also simplifies the
setting of `USE_DISTRIBUTED` (by removing its explicit setting in Python scripts), and deprecate `USE_GLOO_IBVERBS` in favor
of `USE_IBVERBS`.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25879
Differential Revision: D17282395
Pulled By: pietern
fbshipit-source-id: a10735f50728d89c3d81fd57bcd26764e7f84dd1
