build: Replace hard-coded SKIP_MACHINES with generic Cray logic.
build: Replace hard-coded SKIP_MACHINES with generic Cray logic.

StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion,StanfordLegion/legion