90ms vs 45ms
Most of the time is spent in Ion jitted code.
http://llk.github.io/scratch-vm/#119615668 seems to show a similar performance difference
Profiled http://llk.github.io/scratch-vm/#196070469, producing this profile https://share.firefox.dev/3sUnPh0
Looks like a solid 30% of the execution time is spent in js::AtomizeString
Latest Profile: https://share.firefox.dev/3HMupxV
Visually, we are still quite slow compared to Chrome.