Unmute stdlib tests after bootstrap advance.

Author: romanart

libraries/stdlib/test/coroutines/cancellation/CancellationExceptionTest.kt

@@ -18,11 +18,10 @@ class CancellationExceptionTest {
         val message = "message"
         checkException(CancellationException(message, cause), cause, message)
         checkException(CancellationException(message, null), null, message)
-//        checkException(CancellationException(cause), cause, cause.defaultMessage())
+        checkException(CancellationException(cause), cause, cause.defaultMessage())
         checkException(CancellationException(message), null, message)
-        // TODO doesn't work on js ir KT-39964
         checkException(CancellationException(null, cause), cause, null)
-//        checkException(CancellationException(cause = cause), cause, cause.defaultMessage())
+        checkException(CancellationException(cause = cause), cause, cause.defaultMessage())
         // does not work on JVM because of typealias
 //      checkException(CancellationException(message = message), null, message)
         checkException(CancellationException(), null, null)