Since JDK-8307352, itable stub size has grown by 20 bytes on linux-aarch64. In particular, the "slop-counted" code increases from 100->120 bytes, where the current estimate is 124 bytes. I haven't found a case where it exceeds the estimate. For now this size is stable across the few linux-aarch64 configurations I ran with. It doesn't vary (for example) by different klass decoding schemes. But I think the idea of the estimate is that we can never know. I propose we increase the estimate to be safe.