Rollup merge of #142410 - RalfJung:align_of, r=WaffleLapkin,workingjubilee

intrinsics: rename min_align_of to align_of

Now that `pref_align_of` is gone (rust-lang/rust#141803), we can give the intrinsic backing `align_of` its proper name.

r? `@workingjubilee` or `@bjorn3`

Author: matthiaskrgr