clang cannot assemble 9cc's output assembly code.

[youpong]

$ make check
./9cc -test
OK
cd test; make clean check
make[1]: Entering directory '~/9cc/test'
rm -f test *.s *.o a.out core *~
../9cc test.c >test.s
clang -o test.o -c test.s
test.s:1013:2: error: invalid instruction mnemonic 'movzb'
movzb rax, al
^~~~~
test.s:1037:2: error: invalid instruction mnemonic 'movzb'
movzb rax, al
^~~~~
test.s:1066:2: error: invalid instruction mnemonic 'movzb'
movzb rax, al
^~~~~
test.s:1095:2: error: invalid instruction mnemonic 'movzb'
movzb rax, al
^~~~~
test.s:1476:2: error: invalid instruction mnemonic 'movzb'
movzb rax, al
^~~~~
test.s:1591:2: error: invalid instruction mnemonic 'movzb'
movzb rax, al
^~~~~
make[1]: *** [Makefile:26: test.o] Error 1
make[1]: Leaving directory '~/9cc/test'
make: *** [Makefile:28: check] Error 2