heaps: bring back data-compare as heapdata-compare
heaps: bring back data-compare as heapdata-compare

It is useful in several places. Change the name because
0d7233f2daa9c changed the convention and data-* words now
operate on the data directly

mrjbq7/factor,tgunr/factor,bpollack/factor,mrjbq7/factor,AlexIljin/factor,mrjbq7/factor,factor/factor,tgunr/factor,factor/factor,tgunr/factor,bpollack/factor,bpollack/factor,factor/factor,bpollack/factor,AlexIljin/factor,AlexIljin/factor,tgunr/factor,bpollack/factor,factor/factor,factor/factor,mrjbq7/factor,bpollack/factor,tgunr/factor,AlexIljin/factor,factor/factor,AlexIljin/factor,AlexIljin/factor,AlexIljin/factor,bpollack/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor