public long pop() throws DWARFExpressionException {
		if (stack.isEmpty()) {
			throw new DWARFExpressionException("DWARF expression stack empty");
		}
		return stack.pop().longValue();
	}
Indicates that the result of the expression is pointed to by the value in
register {{@link #lastRegister} (ie. lastRegister is a pointer to the result)
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/expression/DWARFExpressionEvaluator.java