Endianness.. and .NET

[bevanweiss]

There's been a recent push by the Dot Net committee to embrace other architectures than just x86_64.
As such there is now a 'supported' architecture which is NOT Little Endian, the IBM s390x.

Testing for this platform is a little tricky. But I have spent almost an entire day playing around with QEMU within Github, and trying to find which distribution I was actually able to get a dotnet installation working on.
It appears Fedora is currently most workable (Alpine is listed by Microsoft, but I couldn't get pre-built binaries under s390x).

It does look like there might be a few conversion issues in this big endianness...

My current test pull request (on my current fork) is here
bevanweiss#2

I haven't yet found a way to have all the QEMU environments run fully. As soon as one crashes out the others are terminated.
But I'd like to avoid doing a manual strategy and separate docker runs.. (without the run-on-arch-action)