Rollup of 7 pull requests

Successful merges:

 - #144072 (update `Atomic*::from_ptr` and `Atomic*::as_ptr` docs)
 - #144151 (`tests/ui/issues/`: The Issues Strike Back [1/N])
 - #144300 (Clippy fixes for miropt-test-tools)
 - #144399 (Add a ratchet for moving all standard library tests to separate packages)
 - #144472 (str: Mark unstable `round_char_boundary` feature functions as const)
 - #144503 (Various refactors to the codegen coordinator code (part 3))
 - #144530 (coverage: Infer `instances_used` from `pgo_func_name_var_map`)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of #144151 - Kivooeo:issue1, r=jieyouxu

`tests/ui/issues/`: The Issues Strike Back [1/N]

I believe I’ve finally brought [my program](https://github.com/Kivooeo/test-manager) to life -- it now handles multiple test moves in one go: plain moves first, then a gentle touch on each file depends on given options. The process should be much smoother now.

Of course, I won’t rush through everything in a few days -- that would be unkind to `@Oneirical.` I’ll pace myself. And also I can't have more than one such PR because `issues.txt` will conflict with previous parts after merging them which is not fun as well.

This PR is just that: first commit - moves; second - regression comments and the occasional .stderr reblesses, also issue.txt and tidy changes. Nothing special, but progress nonetheless. This is for the purpose of preserving test file history during restructuring

Part of #133895.

r? `@jieyouxu`