Allow inlining of `array::map()`

Right now array::map() and array::try_map() do not allow inlining, which makes it not possible to use these convenience methods in performance-sensitive cases and requires writing much more verbose loops.

For example, this doesn't inline:

let lut = rs1.to_le_bytes();
let result = rs2.to_le_bytes().map(|idx| {
    *lut.get(usize::from(idx)).unwrap_or(&0)
});

But this does:

let lut = rs1.to_le_bytes();
let mut result = [0; _];
for (&idx, r) in rs2.to_le_bytes().iter().zip(&mut result) {
    *r = *lut.get(usize::from(idx)).unwrap_or(&0);
}

But the first option is much more natural.

Adding #[inline] on both array::map() and array::try_map() would really help here.

Locate the standard-library definitions of array::map() and array::try_map(), then inspect how their current implementations handle inlining. Add the requested inlining attributes to both methods and verify that the relevant standard-library checks pass and the methods can inline in performance-sensitive use cases.