Revert "hashtables: make hash-combine use fixnum primitives."
Revert "hashtables: make hash-combine use fixnum primitives."

This reverts commit 390dd23261ab6c31bfd38a85048095ca22020643.

AlexIljin/factor,bjourne/factor,factor/factor,factor/factor,dch/factor,mrjbq7/factor,nicolas-p/factor,mrjbq7/factor,bpollack/factor,bjourne/factor,AlexIljin/factor,AlexIljin/factor,factor/factor,dch/factor,tgunr/factor,bpollack/factor,dch/factor,bpollack/factor,tgunr/factor,dch/factor,slavapestov/factor,AlexIljin/factor,factor/factor,dch/factor,bjourne/factor,nicolas-p/factor,slavapestov/factor,slavapestov/factor,bjourne/factor,tgunr/factor,slavapestov/factor,nicolas-p/factor,slavapestov/factor,mrjbq7/factor,AlexIljin/factor,mrjbq7/factor,tgunr/factor,bjourne/factor,bpollack/factor,factor/factor,nicolas-p/factor,mrjbq7/factor,bjourne/factor,bpollack/factor,nicolas-p/factor,slavapestov/factor,dch/factor,bjourne/factor,nicolas-p/factor,tgunr/factor,bpollack/factor,nicolas-p/factor,slavapestov/factor,mrjbq7/factor,factor/factor,tgunr/factor,bpollack/factor,AlexIljin/factor,AlexIljin/factor