Don't pass `vec![]` to `IntoIterator` arguments when not needed

What it does

A method accepting IntoIterator does not need to get a vec![13, 37] and can take a [13, 37] instead.

Advantage

When looking at it with cargo-show-asm Rust seems to optimize away the allocations of vec![] but it still results in more instructions than without it. Using black_box results in the allocations happening which is a lot more instructions than the version with a [T; N].
I assume that in more complex examples these optimizations might not always work resulting in more instructions / allocations happening at runtime. As it results in less instructions with optimizations too it's always a benefit of preferring [T; N] over vec![].

It's also more concise source code.

Drawbacks

requires Rust 1.53

Example

pub fn method<I>(items: I)
where
    I: IntoIterator<Item = u8>,
{
    for entry in items {
        black_box(entry);
    }
}

method(vec![13, 37]);

Could be written as:

method([13, 37]);

Start from the proposed Rust examples and the IntoIterator requirement, then review how Clippy implements comparable lints and handles the Rust 1.53 compatibility constraint. Define the lint's applicable cases and verify that replacing vec![...] with an array preserves the intended iteration behavior and avoids the reported allocation or instruction overhead.