AMD performance testing

[clemekay]

From the 05/07/2025 document "MC/DC Plans Through the End of CEMeNT" :

Currently we are only doing performance testing on Lassen. Enabling the same performance tests to run on AMD is imperative to track our progress as you begin to use our true Exascale class machine.

To these ends, we are developing methods for supporting larger data structures on GPU. We have a proof of concept working on both CUDA and HIP and are now implementing the same techniques in MC/DC