Add uniqueness-error21 based on BabyBear
Add uniqueness-error21 based on BabyBear

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