Please note that the 51% isn't on normal run time! This improvement is when we force ionmonkey to use caches.
This mode is quite similar to running ionmonkey without any type information.
This is important, since sometimes we have bad TI information and we fallback to less specialized code.
Often 10x slower than specialized code. With reusing the baseline stubs (shared stubs) we have a faster fallback.
The shared stub initiative will not help benchmarks, but help regular JS code that happen to fall off
the specialized code paths to be less slow
To put the numbers in perspective
Normal octane score: 27229
Force using caches before: 3780 (7 times slower)
Force using caches after: 5708 (5 times slower)