Changelog #42

#5956 Highlight errors in macros.

#5957 Add consuming modifier to lvalues that are passed by value and not Copy.

#5969 Complete modules based on existing files.

#5990 Implement box patterns.

#5971 Implement async blocks.

#5976 Complete trait impl immediately after type/const/fn.

#5970 Use better heuristics for replacement text when removing dbg!.

#5981 Properly preserve macro braces during dbg! removal.

#5968 Improve generation of Chalk programs.