Redox support

[dhardy]

getrandom/.travis.yml

Line 105 in 199b115

# Redox: wait for https://github.com/rust-lang/rust/issues/60139

Since rust-lang/rust#60139 is still open, we probably don't want to do anything about this yet. In this case however we also need to disable rand tests (see this failure).

[josephlr]

So it looks like rust-lang/libc#1450 is what we need to get redox building again, we shouldn't need the changes to the Rust compiler itself. We just need to wait on upstream libc to merge it and push another release.

[mati865]

Libc CI broke because of migration to Azure Pipelines.

[newpavlov]

I have tried to re-enable Redox CI test, but I got the following error:

component 'rust-std' for target 'x86_64-unknown-redox' is unavailable for download for channel 'nightly'

So IIUC we have to wait for rust-lang/rust#63160.

[josephlr]

We could use the xbuild style commands for Redox. That’s what we do for targets without rust-std