rust 1.51.0 for 32-bit earmv7hf/9.0

[Havard Eidnes <he%NetBSD.org@localhost>]

Hi,

it turns out that rust version 1.51.0 can't be natively built on
a true 32-bit earmv7hf system -- the build of rustc_middle blows
up by exhausting the available data segment size.  There is hope
that rust 1.52.0 is going to improve in this respect, but
meanwhile I've built the 32-bit version in a 32-bit chroot on an
aarch64 NetBSD system.

This takes quite a while, particularly since my aarch64 system is
itself emulated...

For those who would like to skip this particular step, I've
uploaded the resulting binary package to

ftp://ftp.NetBSD.org/pub/NetBSD/misc/he/rust-earmv7hf-9.0-1.51.0.tgz

Regards,

- Håvard