Top rust-clippy issues

Feature request: warn about redundant imports

A-unnecessary E-medium L-lint

Suggest saturating_sub for if i != 0 { i -= 1; }

A-style A-suggestion L-lint

clippy::redundant_pub_crate conflicts with rustc::unreachable_pub

L-bug

Make clone_on_copy lint machine applicable

A-suggestion L-enhancement

Request: A single lint for any usage at all of `as`

L-lint good-first-issue

`clippy-driver` crashes without arguments (index out of bounds)

L-crash

Some extra pedantic checks?

E-medium L-lint T-AST T-macros T-middle good-first-issue

New lint: `while let Some(&x) = slice.iter().next()` is infinite loop

A-correctness A-suggestion L-lint good-first-issue hacktoberfest

Lint methods which have "self" argument but don't use it.

A-complexity A-suggestion L-lint

New lint: transmute of Vec<T> into Vec<U> with different size or alignment is UB