trunk
Replace `:!` binding syntax with phase keywords and contextual defaults (#7479)
Skip `ImplWitnessTable::elements_id` when generating fingerprints (#7629)
Omit empty `observe:` blocks from formatted SemIR. (#7487)
Diagnose when an `impl` is added for something that has a custom witness (#7623)
Change `Destroy` to use a `CustomWitness` instead of a blanket impl (#6512)