Bring back a long-disabled simplification rule.
Bring back a long-disabled simplification rule.

diku-dk/futhark,CulpaBS/wbBach,diku-dk/futhark,diku-dk/futhark,mrakgr/futhark,mrakgr/futhark,diku-dk/futhark,diku-dk/futhark,HIPERFIT/futhark,HIPERFIT/futhark,ihc/futhark,ihc/futhark,mrakgr/futhark,HIPERFIT/futhark,ihc/futhark