Figure out how to unfork from litex-buildenv

[mithro]

It would be good to get foboot and litex-buildenv back into a similar and/or closer platform.

[xobs]

I do most of my development on one of two Windows machines, so I'd prefer to have a solution that is cross-platform.

[mithro]

Weren't you the person who showed that litex-buildenv works under fine under "Base On Windows" as described here -> https://github.com/timvideos/litex-buildenv/wiki/Bash-On-Windows

I'm pretty sure the issue around the C compiler has been resolved now too?

Currently, you need to download newer versions of the compiler that do not statically link glibc, due to Microsoft not implementing the deprecated vsyscall. Linux users will need to do this too if they're running a modern kernel that disables this syscall.

[mithro]

Even if not using the same build environment, we should still be able to share platform definitions + gateware?

[xobs]

There is no longer a dependency on lxsocsupport, so I'll remove that. However, we will need to add the litex_boards repo.