Move kotlin.native.Throws to common stdlib and rename to NativeThrows.

Move native concurrent annotations to subpackage

libraries/stdlib/common/src/kotlin/NativeAnnotations.H.kt

@@ -0,0 +1,24 @@
+/*
+ * 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.native
+
+import kotlin.reflect.KClass
+
+/**
+ * This annotation indicates what exceptions should be declared by a function when compiled to a platform method.
+ *
+ * When compiling to Objective-C/Swift framework, methods having or inheriting this annotation are represented as
+ * `NSError*`-producing methods in Objective-C and as `throws` methods in Swift.
+ * When such a method called through framework API throws an exception, it is either propagated as
+ * `NSError` or considered unhandled (if exception `is` [kotlin.Error] or [kotlin.RuntimeException]).
+ * In any case exception is not checked to be instance of one of the [exceptionClasses].
+ *
+ * @property exceptionClasses the list of checked exception classes that may be thrown by the function.
+ */
+@Target(AnnotationTarget.FUNCTION, AnnotationTarget.CONSTRUCTOR)
+@Retention(AnnotationRetention.SOURCE)
+@OptionalExpectation
+public expect annotation class NativeThrows(vararg val exceptionClasses: KClass<out Throwable>)