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/framework/kt42397/knlibrary.kt

@@ -0,0 +1,12 @@
+// The following 2 singletons are unused. However, since we are generating ObjC bindings for them,
+// they should be marked as used, so that the code generator emits their deinitialization.
+
+object A {
+    fun foo() = 1
+}
+
+class B {
+    companion object {
+        fun foo() = 2
+    }
+}

kotlin-native/backend.native/tests/framework/kt42397/test.swift

@@ -0,0 +1,39 @@
+import Kt42397
+
+class Results {
+    var aFoo: Int32 = 0
+    var bFoo: Int32 = 0
+}
+
+func runTestKt42397(pointer: UnsafeMutableRawPointer) -> UnsafeMutableRawPointer? {
+    autoreleasepool {
+        let results = pointer.bindMemory(to: Results.self, capacity: 1).pointee
+        results.aFoo = A().foo()
+        results.bFoo = B.Companion().foo()
+    }
+
+    return nil
+}
+
+func testKt42397() throws {
+    let results = Results()
+    let resultsPtr = UnsafeMutablePointer<Results>.allocate(capacity: 1)
+    resultsPtr.initialize(to: results)
+    var thread: pthread_t? = nil
+    let result = pthread_create(&thread, nil, runTestKt42397, resultsPtr)
+    try assertEquals(actual: result, expected: 0)
+    pthread_join(thread!, nil)
+
+    try assertEquals(actual: results.aFoo, expected: 1)
+    try assertEquals(actual: results.bFoo, expected: 2)
+}
+
+// -------- Execution of the test --------
+
+class TestTests : SimpleTestProvider {
+    override init() {
+        super.init()
+
+        test("Kt42397", testKt42397)
+    }
+}