@Override
	public final BigInteger getBigInteger(String nm) {
		// Get a "register" value
		return getBigInteger(language.getRegister(nm));
	}
This is a convenience method for reading registers by name. any register name known to the
language can be used as a read location. The associated address space, offset, and size is
looked up and automatically passed to the main getValue routine.

@param nm is the name of the register
@return the unsigned value associated with that register
Ghidra/Framework/Emulation/src/main/java/ghidra/pcode/memstate/AbstractMemoryState.java