[K/N][Tests] Migrate some cinterop tests to new infra

^KT-61259

compiler/testData/codegen/box/cinterop/basics/mangling2.kt

@@ -0,0 +1,23 @@
+// TARGET_BACKEND: NATIVE
+// MODULE: cinterop
+// FILE: mangling2.def
+---
+
+// test mangling of special names
+
+enum Companion {One, Two};
+
+
+// MODULE: main(cinterop)
+// FILE: main.kt
+@file:OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)
+import kotlinx.cinterop.*
+import kotlin.test.*
+import mangling2.*
+
+fun box(): String {
+    val mangled = `Companion$`.Two
+    assertEquals(`Companion$`.Two, mangled)
+    return "OK"
+}
+