Created attachment 634035 [details] [diff] [review]
Kraken crypto-aes/crypto-ccm have a bunch of arrays like [, , , ]. The inner/empty arrays have "unknown properties" because fixArrayType cannot easily determine their type.
This is at least a 10% Kraken crypto-aes/crypto-ccm IonMonkey win since it avoids some GETELEM/SETELEM IC's. JM+TI win is smaller.