New lint suggestion: needles slicing of array

What it does

This lint would detect slicing of arrays looking like arr[..N] or arr[0..N] when arr is of type [T; N]. The only thing this can do is coerce the array to a slice, but that will be either done automatically by the compiler or be better done with as_slice/as_mut_slice.

This lint could also lint against arr[smth..N] to suggest using arr[smth..], but Is this desirable given that clippy currently doesn't even lint slice[0..smth] to suggest slice[..smth]? Maybe good for a second lint.

Advantage

• Removes unnecessary syntax

Drawbacks

The slicing might force a coercion to a slice that makes the thing compile (or with generics could even change behaviour), forcing to use as_slice if removed.

Example

let arr = [0; 10];
println!("{:?}", &arr[..10]);

Could be written as:

let arr = [0; 10];
println!("{:?}", &arr);

The issue does not name a file or test; start by reviewing existing Clippy slicing and array lint implementations and deciding whether the proposed [..N] and [0..N] cases are in scope. Done means the agreed cases are covered with tests, including the coercion and generic-behavior concerns; the arr[smth..N] idea may remain a separate decision.