Auto merge of rust-lang#106275 - Nilstrieb:const-eval-select-me-some-compile-time, r=thomcc

Use some more `const_eval_select` in pointer methods for compile times

Builds on top of rust-lang#105435

`is_aligned_to` is _huge_ with calling `align_offset`, so this should cut it down a lot.

This shows up in rust-lang#65031 (comment)

Author: bors