• Atomic update, getAndUpdate, and updateAndGet operations of MutableStateFlow (#2720).
• Executor.asCoroutineDispatcher implementation improvements (#2601):
  • If the target executor is ScheduledExecutorService, then its schedule API is used for time-related coroutine operations.
  • RemoveOnCancelPolicy is now part of the public contract.
• Introduced overloads for Task.asDeferred and Task.await that accept CancellationTokenSource for bidirectional cancellation (#2527).
• Reactive streams are updated to 1.0.3 (#2740).
• CopyableThrowable is allowed to modify the exception message during stacktrace recovery (#1931).
• CoroutineDispatcher.releaseInterceptedContinuation is now a final method (#2785).
• Closing a Handler underlying Handler.asCoroutineDispatcher now causes the dispatched coroutines to be canceled on Dispatchers.IO (#2778).
• Kotlin is updated to 1.5.20.
• Fixed a spurious ClassCastException in releaseInterceptedContinuation and IllegalStateException from tryReleaseClaimedContinuation (#2736, #2768).
• Fixed inconsistent exception message during stacktrace recovery for non-suspending channel iterators (#2749).
• Fixed linear stack usage for CompletableFuture.asDeferred when the target future has a long chain of listeners (#2730).
• Any exceptions from CoroutineDispatcher.isDispatchNeeded are now considered as fatal and are propagated to the caller (#2733).
• Internal DebugProbesKt (used in the debugger implementation) are moved from debug to core module.