Implementation status update for recent language and library proposals

Hello, Swift community. Now that implementation work on Swift 6.4 has largely wrapped up, the Language Steering Group would like to give a quick implementation status report on recent language and standard library proposals. This covers all accepted proposals not already marked as implemented at the time of the Swift 6.3 release. Proposals implemented in Swift 6.4 SE-0530: Async Result Support SE-0528: Continuation SE-0527: UniqueArray SE-0525: Safe loading API for RawSpan SE-0524: Add withTe...