Illegal instruction in rust programs: paddd

I'm trying out the new "dualboot" feature, so I installed the latest x86 Alpine Linux ("minimal root filesystem" from [here](https://alpinelinux.org/downloads/)) and installed cargo. However, it can't create a new project:

```
~# app add cargo
... installs successfully
~# cargo new hello
Illegal instruction
~# dmesg
40 illegal instruction at 0x56cd15be: 0f fe e1 66 0f df dc 66
~# uname -a
Linux iPhone-ForceBru 4.20.69-ish iSH 1.0 (72) Jun 27 2020 21:15:25 i686 Linux
~#
```

Reproduce `cargo new hello` in the x86 Alpine Linux environment on iSH and collect the `dmesg` output. Investigate handling of the reported `paddd` instruction bytes (`0f fe e1 66 0f df dc 66`); done means the command completes without an illegal-instruction crash.

Written by the indexing model from the issue text.