Add basic bless support

[phansch]

This adds basic bless support. Unfortunately without support for miri because I wasn't able to untangle it properly so far.

Should be merged after #232

[phansch]

So, the second commit adds a new testsuite as well. I think it's an improvement over the current one because it allows to quickly add new tests for different compiletest configurations. In this case for the bless config.
If we wanted to test bless support the old way, we would have to create a second test-project. The same for any other configuration.

It's a simplified version of cargo-test-support. If we ever unify both compiletest variants, it should be possible to keep that testsuite to avoid unexpected bugs.

[phansch]

triggering a new build

[phansch]

Looks like the GitHub API is having a bad moment:

Warning: Failed to download action 'api.github.com/repos/actions/checkout/zipball/5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f'. Error: Response status code does not indicate success: 500 (Internal Server Error).

https://www.githubstatus.com/incidents/5qdkkyg958vy

[Munksgaard]

Not quite sure what's going on here. Any guess @phansch ?

[Manishearth]

The nightly build is failing

error[E0560]: struct `TestOpts` has no field named `filter`
   --> src/lib.rs:114:9
    |
114 |         filter: config.filter.clone(),
    |         ^^^^^^ help: a field with a similar name exists: `filters`

[phansch]

Odd, I can't reproduce the error above locally, let's see if a rebase fixes it. nevermind, can reproduce it now

[phansch]

This is due to rust-lang/rust#81356, I'll try and see if I can get it upstreamed into the tester crate later today. Otherwise, we'll need to use filters only if the rustc feature is enabled.

[phansch]

@Munksgaard Thank you for the quick merge! Do you think it would be possible to release a 0.6 version as well?

[Munksgaard]

Yes, I'll do that when the CI for #225 passes :)

[Munksgaard]

Done!