Introduce CancellationException

#KT-39126 Fixed

libraries/stdlib/src/kotlin/coroutines/cancellation/CancellationExceptionH.kt

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package kotlin.coroutines.cancellation
+
+/**
+ * Thrown by cancellable suspending functions if the coroutine is cancelled while it is suspended.
+ * It indicates _normal_ cancellation of a coroutine.
+ */
+@ExperimentalStdlibApi
+@SinceKotlin("1.4")
+public expect open class CancellationException : IllegalStateException {
+    public constructor()
+    public constructor(message: String?)
+}
+
+/**
+ * Creates an instance of [CancellationException] with the given [message] and [cause].
+ */
+@ExperimentalStdlibApi
+@SinceKotlin("1.4")
+@Suppress("FunctionName", "NO_ACTUAL_FOR_EXPECT")
+public expect fun CancellationException(message: String?, cause: Throwable?): CancellationException
+
+/**
+ * Creates an instance of [CancellationException] with the given [cause].
+ */
+@ExperimentalStdlibApi
+@SinceKotlin("1.4")
+@Suppress("FunctionName", "NO_ACTUAL_FOR_EXPECT")
+public expect fun CancellationException(cause: Throwable?): CancellationException