Tests on migrating main thread and memory leaks with interop (#4494)

kotlin-native/backend.native/tests/interop/migrating_main_thread/main.cpp

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2010-2020 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.
+ */
+
+#include "testlib_api.h"
+
+#include <cassert>
+#include <thread>
+
+int main() {
+    std::thread main1([]() {
+        assert(testlib_symbols()->kotlin.root.readFromA() == 0);
+        testlib_symbols()->kotlin.root.writeToA(1);
+        assert(testlib_symbols()->kotlin.root.readFromA() == 1);
+    });
+    main1.join();
+
+    std::thread main2([]() {
+        // Globals were reinitialized.
+        assert(testlib_symbols()->kotlin.root.readFromA() == 0);
+    });
+    main2.join();
+
+    return 0;
+}