Use `is_aligned_to` in `FromBytes` once it's available

[wedsonaf]

We currently do a "manual" check for alignment.

#1037 (comment)

[ojeda]

Added to the list.

[obeis]

I am going to work on it. Can someone please assign it to me?

[y86-dev]

the feature pointer_is_aligned has not yet been stabilized, see rust-lang/rust#96284

[ojeda]

is_aligned() is getting stabilized in 1.79 (is_aligned_to() got split into another feature gate).