Fix handling of shape declarations.
Fix handling of shape declarations.

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