Implement Show for DList
relicense shootout-regex-dna.rs

Part of #14248

The authors are @pcwalton and @BurntSushi, and we have their agreement.
Implement Show for SmallIntMap
auto merge of #14725 : aochagavia/rust/show, r=alexcrichton
Fix PartialEq documentation with regards to floats

It is in fact the case that `NaN != NaN`. The true relations for
compareQuietNotEqual are LT, GT *and* UN.

I also rephrased the docs for PartialOrd since floats are not the only
types which are not totally ordered.
Clarify restrictions on ne

I can't think of any sane cases where this restriction would not hold,
and the standard library seems to assume it pretty much everywhere.
auto merge of #14733 : sfackler/rust/partial-eq-nan-docs, r=alexcrichton

It is in fact the case that `NaN != NaN`. The true relations for
compareQuietNotEqual are LT, GT *and* UN.

I also rephrased the docs for PartialOrd since floats are not the only
types which are not totally ordered.
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It has been superseded by the unused_attribute lint.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]
Improve error message for range in match

Range allows char and numeric types, but previous error message
mentioned only numeric types.
Add back hint for crate level attributes
Remove unused name_str_pair method
auto merge of #14743 : Sawyer47/rust/range-msg, r=huonw

Range allows char and numeric types, but previous error message
mentioned only numeric types.
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.