public DWARFLineProgramState nextRow() throws IOException {
		while (hasNext()) {
			DWARFLineProgramInstruction instr = step();
			if (instr.row() != null) {
				return instr.row();
			}
		}
		return null;
	}
Handles executing, step-by-step, the address-to-sourcefile mapping instructions found at the
end of a DWARFLine structure.
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/line/DWARFLineProgramExecutor.java