Simplify away single-iteration maps.
Simplify away single-iteration maps.

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