Avoid duplicate listings in futhark-doc.
Avoid duplicate listings in futhark-doc.

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