[XROS][ML] System specific adjustments for UTs to work. (#65245)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65245
Building and running c10 and qnnpack tests on XROS.
Notable changes:
- Adding #if define(_XROS_) in few places not supported by XROS
- Changing Threadpool to abstract class
ghstack-source-id: 139513579
Test Plan: Run c10 and qnnpack tests on XROS.
Reviewed By: veselinp, iseeyuan
Differential Revision: D30137333
fbshipit-source-id: bb6239b935187fac712834341fe5a8d3377762b1
