benchmark.json: adding a json benchmark.
benchmark.json: adding a json benchmark.

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