Remove unneeded default imports in stdlib and tests

libraries/stdlib/coroutines-experimental/jvm/src/kotlin/coroutines/experimental/SafeContinuationJvm.kt

@@ -2,10 +2,10 @@
  * Copyright 2010-2018 JetBrains s.r.o. 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.experimental
 
 import java.util.concurrent.atomic.AtomicReferenceFieldUpdater
-import kotlin.*
 import kotlin.coroutines.experimental.intrinsics.COROUTINE_SUSPENDED
 
 @PublishedApi

libraries/stdlib/coroutines-experimental/src/kotlin/coroutines/experimental/SequenceBuilder.kt

@@ -9,7 +9,6 @@
 
 package kotlin.coroutines.experimental
 
-import kotlin.*
 import kotlin.coroutines.experimental.intrinsics.*
 import kotlin.experimental.ExperimentalTypeInference