Rollup of 5 pull requests
Successful merges:
- #69372 (Updates links in various Compiler Error Index entries)
- #69385 (Relax str::get_unchecked precondition to permit empty slicing)
- #69386 (Fix minor error in `MaybeUninit::get_mut()` doc example)
- #69394 (Clean up E0367 explanation)
- #69405 (docs: Stdin::read_line: mention the appending)
Failed merges:
r? @ghost