protected final long arrayIndexForCursor(long currentHead) {
        return arrayIndexForCursor(mask, referenceMessageSize, currentHead);
    }
Computes an index relative to the buffer start for an offset. This does
not recover the original index because that is a very <b>hard</b>
problem.

@param bufferAddress
@param messageSize
@param offset
@return
jctools-channels/src/main/java/org/jctools/channels/OffHeapFixedMessageSizeRingBuffer.java