[K/N][tests] Migrate various runtime/ tests ^KT-61259

native/native.tests/testData/codegen/variables/var1.kt

@@ -0,0 +1,28 @@
+import kotlin.test.*
+
+private class Integer(val value: Int) {
+    operator fun inc() = Integer(value + 1)
+}
+
+private fun foo(x: Any, y: Any) {
+    x.use()
+    y.use()
+}
+
+fun box(): String {
+    var x = Integer(0)
+
+    for (i in 0..1) {
+        val c = Integer(0)
+        if (i == 0) x = c
+    }
+
+    // x refcount is 1.
+
+    foo(x, ++x)
+    return "OK"
+}
+
+private fun Any?.use() {
+    var x = this
+}