Vadim Petrochenkov

I've rebased, but this still needs an approval from at least 2 compiler team members (ping @estebank @matthewjasper @pnkfelix @wesleywiser).

@ehuss No, should it? The attribute only has effect on details of produced binaries, but not on anything else in the language.

Okay, I've lang nominated this PR.

Looking at the existing uses of `opts.verbose` it indeed affects the debugging output of the compiler itself, rather than debuginfo in the produced binaries.

So, what are the goals here: - We want to have a possibility to add new auto traits that are added to *all* bound lists by default on the current...

The issue right now is that there are regressions, some previously passing code now fails due to cycles in trait solver or something similar, @Bryanskiy has been trying to investigate...

@lcnr From what I know the cycles appear in some tests in the ui test suite, those are sufficiently minimized. They should be visible in this PR when it's updated.

@bors try @rust-timer queue

I'm still going to run crater on this, even if there will clearly be regressions due to cycles, just to estimate the scale of their effect.

Silly question - why doesn't `Sized` have similar issues with cycles? Can we make the new traits more like `Sized` and less like `Send`?