Add validation to ensure `iterations` is greater than zero and create ùsage()`

File CodeGeneratorDriver.cpp

Insert a check to ensure the iterations variable is greater than zero.

try{
	iterations = std::stoi(argv[1]);
}catch(const std::invalid_argument& e)
{
	std::cout << “Number of iterations should be integer!” << std::endl;
	return 1;
}

Create a usage() function for this code snippet.

if (argc < 6) {
	std::cout << “ERROR! Missing arguments!” << std::endl;
	std::cout << “Please provide Number of Iterations, Production Rules, Seed String File, Output Folder Name and Variable Type.” << std::endl;
	std::cout << “Usage: ./benchGen <number_of_iterations> <production_rules_file> <seed_string_file> <bench_name> <var_type>” << 		std::endl;
	return 1;
}

Start in src/gen/CodeGeneratorDriver.cpp and read its current command-line argument parsing. Check the behavior for missing arguments, non-integer iterations, and zero or negative iterations. Done means invalid inputs produce clear errors and the usage message is available through the requested usage() function.