Joran Dirk Greef 843c104fc9 Add io_uring syscalls to os.bits.linux.mips.SYS
As per lib/libc/musl/arch/mips/bits/syscall.h.in:

```c
```
2020-09-21 10:39:58 +02:00
..
2020-09-20 19:51:23 +02:00