swift

ced17561 - [Concurrency/Distributed] ensure distributed thunks are @concurrent

[Concurrency/Distributed] ensure distributed thunks are @concurrent Otherwise the "nonisolated nonsending by default" mode blows up as distributed thunk signatures dont match expectations. This undoes the fix from https://github.com/swiftlang/swift/pull/83940 and applies the fix on the synthesis side of the distributed thunks, such that they are @concurrent always -- which keeps their old semantics basically, regardless of what "default" mode we have.