fix x86_64 wrongly reporting itself as ILP32 instead of LP64
[musl] / arch / x86_64 /
drwxr-xr-x   ..
-rw-r--r-- 2345 atomic.h
drwxr-xr-x - bits
-rw-r--r-- 132 pthread_arch.h
-rw-r--r-- 12493 syscall.h