These have been replaced by more reliable checks in the compiler itself.

Note that this doesn't test consistency of some properties, like `reason`.

[NLL] Use smaller spans for errors involving closure captures

Closes #51170
Closes #46599

Error messages involving closures now point to the captured variable/closure args.

r? @pnkfelix

avoid computing liveness for locals that escape into statics

Fixes #52713

I poked at this on the plane and I think it's working -- but I want to do a bit more investigation and double check. The idea is to identify those local variables where the entire value will "escape" into the return -- for them, we don't need to compute liveness, since we know that the outlives relations from the return type will force those regions to be equal to free regions. This should help with html5ever in particular.

- [x] test performance
- [x] verify correctness
- [x] add comments

r? @pnkfelix
cc @lqd

Update cargo to fix Rust 2018 build scripts

Update rustfmt, RLS, Clippy

r? @kennytm

Fixes RLS build and updates RLS and Rustfmt to their 1.0 RCs