flattening: reuse outermost size for segdescp
flattening: reuse outermost size for segdescp

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