Rollup of 4 pull requests
Successful merges:
- #116675 ([ptr] Document maximum allocation size)
- #124997 (Fix ICE while casting a type with error)
- #125072 (Add test for dynamic dispatch + Pin::new soundness)
- #125090 (Migrate fuchsia docs from `pm` to `ffx`)
r? `@ghost`
`@rustbot` modify labels: rollup