Make fib.l0 use new loop syntax.
Make fib.l0 use new loop syntax.

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