This PR changes AMG defaults regarding GPUs at various places, adds regression tests on GPUs, simplifies CUDA boxloop implementations.
Co-authored-by: Sarah Virginia Osborn <osborn9@llnl.gov>
Co-authored-by: PaulMullowney <pmullown@nrel.gov>
Co-authored-by: Daniel Osei-Kuffuor <oseikuffuor1@llnl.gov>
Co-authored-by: Ruipeng Li <li50@euler.llnl.gov>
Co-authored-by: Ruipeng Li <coe0141@redwood.cm.cluster>
