@Override
	public RegisterValue getRegisterValue(Register register) {
		if (!register.isProcessorContext()) {
			throw new UnsupportedOperationException();
		}
		if (register.equals(contextReg)) {
			return contextRegValue;
		}
		return new RegisterValue(register, contextRegValue.toBytes());
	}
Set those bits in the nonFlowingContextRegisterMask which should not 
flow with context.
@param reg context register piece
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/emulate/EmulateDisassemblerContext.java