Cleanup: Move src/test/run-fail to src/test/ui

[Centril]

We have a small amount of tests in src/test/run-fail; these should be moved over to various directories in src/test/ui depending on what the test is about. (See #65438 (comment) for one example of moving run-fail/ tests to ui/.) When moving each test in src/test/run-fail you have to add // run-fail to the top of each file.

cc @varkor

This issue has been assigned to @nvlbg via this comment.

[nvlbg]

I'd like to work on this. First time contributor so it make take me some time to finish it.

[Centril]

@rustbot assign @nvlbg

[estebank]

Note that some of those tests are still there due to non-determinism in the output across multiple platforms. Those should be restricted to run on only one platform to be able to do this move.

[varkor]

Those should be restricted to run on only one platform to be able to do this move.

We should make sure to cross reference these with issues too.

[nvlbg]

@estebank are these tests marked somehow? Also how are tests restricted to a single platform?

Edit: I found the following comments in the tests:

// ignore-cloudabi no std::process
// ignore-cloudabi no std::process
// ignore-cloudabi no std::process
// ignore-cloudabi no std::process
// ignore-cloudabi no std::process
// ignore-emscripten Needs threads
// ignore-emscripten Needs threads.
// ignore-emscripten Needs threads.
// ignore-emscripten
// ignore-emscripten
// ignore-emscripten
// ignore-cloudabi no std::env

Are those the flags that some platforms need to be ignored?

[estebank]

I believe those in particular aren't the ones u was thinking about, but they are marked with ignore- tags. I think they might be either ignore-x86 or ignore-musl, something along those lines.

[Centril]

Generally speaking, a trial and error approach should work here... work through the tests a few at a time and see what will go through CI.