buildds: rv-osuosl-01 vs rv-mullvad-03

[Mathieu Malaterre <malat@debian.org>]

Dear riscv porters,

Could someone please tell me what is the actual difference between
rv-osuosl-01 and rv-mullvad-03 buildds ?

I did not see them listed at:

* https://db.debian.org/machines.cgi

It appears that at least one of my package does not build successfully
on rv-osuosl-01 (*). I could not reproduce the issue of 'Illegal
instruction' neither on my local schroot/qemu setup nor on real
hardware (lab.rvperf.org).

Thanks

(*) https://buildd.debian.org/status/logs.php?pkg=highway&ver=1.0.0-5&arch=riscv64