relicense shootout-regex-dna.rs

Part of #14248

The authors are @pcwalton and @BurntSushi, and we have their agreement.
Add visit_attribute to Visitor, use it for unused_attribute

The lint was missing a *lot* of cases previously.
Remove the attribute_usage lint

It has been superseded by the unused_attribute lint.

[breaking change]
Add back hint for crate level attributes
Remove unused name_str_pair method
std::io: expand the oneshot/periodic docs.

Examples!

Fixes #14714.
auto merge of #14728 : TeXitoi/rust/relicense-shootout-regex-dna, r=brson

Part of #14248

The authors are @pcwalton and @BurntSushi, and we have their agreement.

@brson OK?
auto merge of #14741 : sfackler/rust/visit-attr, r=alexcrichton

The lint was missing a *lot* of cases previously.
auto merge of #14745 : huonw/rust/timer-doc, r=alexcrichton

std::io: expand the oneshot/periodic docs.

Examples!

Fixes #14714.
Implement Hash for Bitv and BitvSet

Closes #14744
auto merge of #14749 : sfackler/rust/bitv-hash, r=alexcrichton

Closes #14744
Fix spelling errors in comments.
auto merge of #14751 : jbcrail/rust/fix-comments, r=alexcrichton
relicense shootout-fannkuch-redux.rs

Part of #14248

Main contributors are @pcwalton, @alexcrichton and me.  Only
@dguenther appear in git blame as a minor contribution, but it is
only adding the rust license, so removed by this relicensing.
auto merge of #14756 : TeXitoi/rust/relicense-shootout-fannkuch-redux, r=brson

Part of #14248

Main contributors are @pcwalton, @alexcrichton and me.  Only
@dguenther appear in git blame as a minor contribution, but it is
only adding the rust license, so removed by this relicensing.

@brson OK?
Converted PortReader and ChanWriter to use Vec.
auto merge of #14765 : rapha/rust/master, r=alexcrichton
Provide a witness pattern for non-exhaustive patterns

Fixed #4321
Check pattern refutability the same way exhaustiveness is checked
Add support for fixed size vectors in let/arg patterns

Fixes #7784