[Native][Tests] Move existing CExport tests under the InterfaceV1 dir

To avoid collisions with the future InterfaceNone tests

native/native.tests/testData/CExport/InterfaceV1/kt36639/main-main.out

@@ -0,0 +1,6 @@
+CFoo1::extfoo
+CFoo1::extfoo
+CFoo2::extfoo
+CFoo2::extfoo
+Int::extfoo
+Int::extfoo

native/native.tests/testData/CExport/InterfaceV1/kt36639/main.c

@@ -0,0 +1,28 @@
+#include "kt36639_api.h"
+
+#define __ kt36639_symbols()->
+#define T_(x) kt36639_kref_ ## x
+
+
+int
+main() {
+  T_(CFoo1) foo1 = __ kotlin.root.CFoo1.CFoo1();
+  T_(CFoo2) foo2 = __ kotlin.root.CFoo2.CFoo2();
+  T_(kotlin_Int) intV = __ createNullableInt(42);
+  T_(kotlin_Any) any;
+  T_(Foo) foo = { .pinned = foo1.pinned };
+
+  any.pinned = foo1.pinned;
+  __ kotlin.root.CFoo1.callMe(foo1, any);
+  __ kotlin.root.Foo.extfoo(foo, any);
+  any.pinned = foo2.pinned;
+  __ kotlin.root.CFoo1.callMe(foo1, any);
+  __ kotlin.root.Foo.extfoo(foo, any);
+  any.pinned = intV.pinned;
+  __ kotlin.root.CFoo1.callMe(foo1, any);
+  __ kotlin.root.Foo.extfoo(foo, any);
+
+  __ DisposeStablePointer(foo1.pinned);
+  __ DisposeStablePointer(foo2.pinned);
+  __ DisposeStablePointer(intV.pinned);
+}

native/native.tests/testData/CExport/InterfaceV1/kt36639/main.kt

@@ -0,0 +1,21 @@
+interface Foo {
+    fun Any.extfoo()
+}
+
+class CFoo1:Foo {
+    override fun Any.extfoo() {
+        when(this) {
+            is CFoo1 -> println("CFoo1::extfoo")
+            is CFoo2 -> println("CFoo2::extfoo")
+            is Int -> println("Int::extfoo")
+        }
+    }
+
+    fun callMe(arg: Any) = arg.extfoo()
+}
+
+class CFoo2:Foo {
+    override fun Any.extfoo() {
+        TODO("Not yet implemented")
+    }
+}

native/native.tests/testData/CExport/InterfaceV1/smoke0/main.c

@@ -0,0 +1,7 @@
+#include "smoke0_api.h"
+
+int main() {
+    if (foo() != 42) {
+        return -1;
+    }
+}

native/native.tests/testData/CExport/InterfaceV1/smoke0/main.kt

@@ -0,0 +1,8 @@
+@file:OptIn(kotlin.experimental.ExperimentalNativeApi::class)
+
+import kotlin.native.CName
+
+@CName("foo")
+fun foo(): Int {
+    return 42
+}