Move everything under kotlin-native folder

I was forced to manually do update the following files, because otherwise
they would be ignored according .gitignore settings. Probably they
should be deleted from repo.

Interop/.idea/compiler.xml
Interop/.idea/gradle.xml
Interop/.idea/libraries/Gradle__org_jetbrains_kotlin_kotlin_runtime_1_0_3.xml
Interop/.idea/libraries/Gradle__org_jetbrains_kotlin_kotlin_stdlib_1_0_3.xml
Interop/.idea/modules.xml
Interop/.idea/modules/Indexer/Indexer.iml
Interop/.idea/modules/Runtime/Runtime.iml
Interop/.idea/modules/StubGenerator/StubGenerator.iml
backend.native/backend.native.iml
backend.native/bc.frontend/bc.frontend.iml
backend.native/cli.bc/cli.bc.iml
backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2Native.kt
backend.native/cli.bc/src/org/jetbrains/kotlin/cli/bc/K2NativeCompilerArguments.kt
backend.native/tests/link/lib/foo.kt
backend.native/tests/link/lib/foo2.kt
backend.native/tests/teamcity-test.property

kotlin-native/backend.native/tests/codegen/function/referenceBigArity.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2010-2019 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license
+ * that can be found in the LICENSE file.
+ */
+
+package codegen.function.referenceBigArity
+
+import kotlin.test.*
+
+fun фу(а: Int, б: Int, в: Int, г: Int, д: Int, е: Int, ё: Int, ж: Int, з: Int, и: Int, й: Int, к: Int,
+       л: Int, м: Int, н: Int, о: Int, п: Int, р: Int, с: Int, т: Int, у: Int, ф: Int, х: Int, ц: Int,
+       ч: Int, ш: Int, щ: Int, ъ: Int, ы: Int, ь: Int, э: Int, ю: Int, я: Int): Int {
+    return а + б + в + г + д + е + ё + ж + з + и + й + к + л + м + н + о +
+            п + р + с + т + у + ф + х + ц + ч + ш + щ + ъ + ы + ь + э + ю + я
+}
+
+@Test fun runTest() {
+    val ref = ::фу
+    println(ref(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
+            17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32))
+}