汇编代码转成机器码——对输入有几点要求：指令是小写；一行只能有一条指令；每行开头不能有空格，必须一上来就是操作符，后面可以有空格；立即数只处理十进制数；输入-1代表程序结束-Turn assembly code into machine code- there are several points of entry requirements: command is lowercase line can only have one instruction beginning of each l