Introduce expect KFunction in common

libraries/stdlib/jvm/src/kotlin/reflect/KFunction.kt

@@ -8,7 +8,7 @@ package kotlin.reflect
 /**
  * Represents a function with introspection capabilities.
  */
-public interface KFunction<out R> : KCallable<R>, Function<R> {
+public actual interface KFunction<out R> : KCallable<R>, Function<R> {
     /**
      * `true` if this function is `inline`.
      * See the [Kotlin language documentation](https://kotlinlang.org/docs/reference/inline-functions.html)

libraries/stdlib/src/kotlin/reflect/KFunction.kt

@@ -0,0 +1,11 @@
+/*
+ * Copyright 2010-2018 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.reflect
+
+/**
+ * Represents a function with introspection capabilities.
+ */
+public expect interface KFunction<out R> : KCallable<R>, Function<R>