Make CoroutineStart.ATOMIC experimental as it covers important use-case with resource cleanup in finally block

Add missing @InternalCoroutinesApi
Fixes #627

Author: qwwdfsad

common/kotlinx-coroutines-core-common/src/CancellableContinuation.kt

@@ -231,6 +231,7 @@ public fun CancellableContinuation<*>.removeOnCancel(node: LockFreeLinkedListNod
  * Removes a given node on cancellation.
  * @suppress **This is unstable API and it is subject to change.**
  */
+@InternalCoroutinesApi
 public fun CancellableContinuation<*>.removeOnCancellation(node: LockFreeLinkedListNode) =
     invokeOnCancellation(handler = RemoveOnCancel(node).asHandler)
 

common/kotlinx-coroutines-core-common/src/CompletedExceptionally.kt

@@ -17,7 +17,7 @@ import kotlin.coroutines.experimental.*
  *        or artificial [CancellationException] if no cause was provided
  * @suppress **This is unstable API and it is subject to change.**
  */
-// todo: rename to Cancelled
+@InternalCoroutinesApi
 open class CompletedExceptionally(
     @JvmField public val cause: Throwable
 ) {
@@ -34,6 +34,7 @@ open class CompletedExceptionally(
  *        if created on first access to [exception] property.
  * @suppress **This is unstable API and it is subject to change.**
  */
+@InternalCoroutinesApi
 public class CancelledContinuation(
     continuation: Continuation<*>,
     cause: Throwable?

common/kotlinx-coroutines-core-common/src/CoroutineStart.kt

@@ -54,10 +54,8 @@ public enum class CoroutineStart {
      *
      * Cancellability of coroutine at suspension points depends on the particular implementation details of
      * suspending functions as in [DEFAULT].
-     *
-     * @suppress **This an internal API and should not be used from general code.**
      */
-    @InternalCoroutinesApi
+    @ExperimentalCoroutinesApi
     ATOMIC,
 
     /**

common/kotlinx-coroutines-core-common/src/Dispatched.kt

@@ -118,6 +118,7 @@ internal fun <T> Continuation<T>.resumeDirectWithException(exception: Throwable)
 /**
  * @suppress **This is unstable API and it is subject to change.**
  */
+@InternalCoroutinesApi
 public interface DispatchedTask<in T> : Runnable {
     public val delegate: Continuation<T>
     public val resumeMode: Int get() = MODE_CANCELLABLE
@@ -158,6 +159,7 @@ public interface DispatchedTask<in T> : Runnable {
 /**
  * @suppress **This is unstable API and it is subject to change.**
  */
+@InternalCoroutinesApi
 public fun <T> DispatchedTask<T>.dispatch(mode: Int = MODE_CANCELLABLE) {
     var useMode = mode
     val delegate = this.delegate

common/kotlinx-coroutines-core-common/src/Job.kt

@@ -411,6 +411,7 @@ public inline fun DisposableHandle(crossinline block: () -> Unit) =
  *
  * @suppress **This is unstable API and it is subject to change.**
  */
+@InternalCoroutinesApi
 internal interface ChildJob : Job {
     /**
      * Parent is cancelling its child by invoking this method.
@@ -419,6 +420,7 @@ internal interface ChildJob : Job {
      *
      * @suppress **This is unstable API and it is subject to change.**
      */
+    @InternalCoroutinesApi
     public fun parentCancelled(parentJob: Job)
 }
 
@@ -427,6 +429,7 @@ internal interface ChildJob : Job {
  *
  * @suppress **This is unstable API and it is subject to change.**
  */
+@InternalCoroutinesApi
 internal interface ChildHandle : DisposableHandle {
     /**
      * Child is cancelling its parent by invoking this method.
@@ -436,6 +439,7 @@ internal interface ChildHandle : DisposableHandle {
      *
      * @suppress **This is unstable API and it is subject to change.**
      */
+    @InternalCoroutinesApi
     public fun childCancelled(cause: Throwable): Boolean
 }