Constant MAX_BYTES_TO_HASH

const MAX_BYTES_TO_HASH: usize = 64;

This is the maximum size we will hash at a time, when interning an Allocation and its InitMask. Note, we hash that amount of bytes twice: at the start, and at the end of a buffer. Used when these two structures are large: we only partially hash the larger fields in that situation. See the comment at the top of their respective Hash impl for more details.