Better parse errors for unexpected doc comments.
Better parse errors for unexpected doc comments.

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