This commit removes the comment in emulate_intrinsic, which is
currently referring to 'src/librustc_middle/ty/constness.rs'.

…imulacrum

Simplify [a]rc code a little

Nothing interesting, just make [a]rc code a little nicer by using `byte_sub` and `let`-`else`.

Add label for generic arg (+ APIT) and RPIT callables in `label_fn_like`

Fixes rust-lang#98308

… r=notriddle

removed unused CSS and unused HTML IDs

I think that should cover most remaining unused CSS/HTML IDs.

r? `@notriddle`

…, r=tmiasko

Add myself to the set of people notified when MIR changes.

I would like to be notified when changes to MIR are made.

Remove comment referring to constness.rs

This commit removes the comment in emulate_intrinsic, which is
currently referring to `src/librustc_middle/ty/constness.rs`.

Add regression test for rust-lang#89436

I never got around to adding such a test.

In general I think the `yoke` crate has a bunch of interesting testcases that exercise various edges of the algorithms here, it would be nice if we could simply depend on the crate and add some tests that exercise it, but I don't think that's possible. Do you or `@eddyb` think there's any use trying to upstream a bunch of common yoke minimal working example code to the testsuite and having a ton of yoke tests?