This adds to RDNRND to Goldmont as I believe it has that feature in addition to RDSEED.
I don't know how to test the MOVBE part since we don't have a MOVBE macro nor do we need one. The backend will already infer the feature from the CPU name. We do have a command line switch to force it on and off regardless of CPU. So really I don't even think this change is necessary, I just found it inconsistent that the movbe handling existed for the command line option, but was not bound to any CPU.