Unpark runBlocking thread on coroutine completion instead of cancellation

Fixes #501

Author: qwwdfsad

core/kotlinx-coroutines-core/src/Builders.kt

@@ -56,7 +56,7 @@ private class BlockingCoroutine<T>(
         if (privateEventLoop) require(eventLoop is BlockingEventLoop)
     }
 
-    override fun onCancellationInternal(exceptionally: CompletedExceptionally?) {
+    override fun onCompletionInternal(state: Any?, mode: Int) {
         // wake up blocked thread
         if (Thread.currentThread() != blockedThread)
             LockSupport.unpark(blockedThread)

core/kotlinx-coroutines-core/test/RunBlockingTest.kt

@@ -66,4 +66,20 @@ class RunBlockingTest : TestBase() {
         finish(4)
         thread.close()
     }
+
+
+    @Test
+    fun testCancellation() {
+        val job = launch(DefaultDispatcher) {
+            runBlocking(coroutineContext) {
+                while(true) {
+                    yield()
+                }
+            }
+        }
+
+        runBlocking {
+            job.cancelAndJoin()
+        }
+    }
 }