private void setBit(byte[] byteMask, int bit) {
		int byteNum = byteMask.length - (bit / 8) - 1;
		int bitNum = bit % 8;
		byteMask[byteNum] |= (1 << bitNum);
	}
Returns the mask that indicates which bits in the base register apply to this register.

@return the mask that indicates which bits in the base register apply to this register
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/lang/Register.java