public BigInteger getValue(Register register, Address address, boolean signed) {
		return getValue(register, Address.NO_ADDRESS, address, signed);
	}
Returns the future register value at the specified address.  If no future value is stored,
it will return the value stored in the program.

Use this method if keeping separate flows from different flow from addresses is not important.

@param register the register to get a value for.
@param address the address at which to get a value.
@param signed if true, interpret the value as signed.
@return the value of the register at the location, or null if a full value is not established.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/disassemble/DisassemblerContextImpl.java