Introduce createCoroutineUnchecked intrinsic

Also use it for buildSequence implenentation

 #KT-16155 Fixed

libraries/stdlib/common/src/kotlin/CoroutinesH.kt

@@ -14,14 +14,3 @@ internal header class SafeContinuation<in T> : Continuation<T> {
     override fun resume(value: T): Unit
     override fun resumeWithException(exception: Throwable): Unit
 }
-
-@SinceKotlin("1.1")
-internal header fun <T> (suspend () -> T).createCoroutineInternal(
-        completion: Continuation<T>
-): Continuation<Unit>
-
-@SinceKotlin("1.1")
-internal header fun <R, T> (suspend R.() -> T).createCoroutineInternal(
-        receiver: R,
-        completion: Continuation<T>
-): Continuation<Unit>

libraries/stdlib/common/src/kotlin/CoroutinesIntrinsicsH.kt

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlin.coroutines.experimental.intrinsics
+
+import kotlin.coroutines.experimental.Continuation
+
+@SinceKotlin("1.1")
+public header fun <T> (suspend () -> T).createCoroutineUnchecked(
+        completion: Continuation<T>
+): Continuation<Unit>
+
+@SinceKotlin("1.1")
+public header fun <R, T> (suspend R.() -> T).createCoroutineUnchecked(
+        receiver: R,
+        completion: Continuation<T>
+): Continuation<Unit>