rustup: Don't do verbose tarball extraction

This creates an enormous amount of spew.
Update complement-bugreport.md

`--version=verbose` doesn't exist anymore, `--version --verbose` is the way to do that now.
Fix `collections::VecMap`'s `PartialEq` implementation

Previously it took capacity into account.

Additionally remove the `ne` implementation of `RingBuf` which is the default
one anyway.
Fix some spelling errors.
Merge pull request #19886 from brson/rustup

rustup: Don't do verbose tarball extraction

Reviewed-by: alexcrichton
Merge pull request #20001 from huonw/speeling2

Fix some spelling errors.

Reviewed-by: nick29581
Merge pull request #20153 from brianloveswords/patch-1

Update complement-bugreport.md

Reviewed-by: alexcrichton
Merge pull request #20155 from tbu-/pr_vecmap_fiximpls

Fix `collections::VecMap`'s `PartialEq` implementation

Reviewed-by: Gankro
Require types to opt-in Sync
Rename `OwnedPtr` to `UniquePtr`
Make Send and Sync traits unsafe
Move RacyCell to `std::comm`

RacyCell is not exactly what we'd like as a final implementation for
this. Therefore, we're moving it under `std::comm` and also making it
private.
Implement `Sync` for some windows sys types
Rename `UniquePtr` to `Unique`

Mostly following the convention in RFC 356
Relax `Arc` bounds don't require Sync+Send

Besides the above making sense, it'll also allow us to make `RacyCell`
private and use UnsafeCell instead.
Keep track of the whole error chain