Add ppTupleLambda to prettyprinter.
Add ppTupleLambda to prettyprinter.

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