[K/N] Add more tests on associated object handling ^KT-56233

kotlin-native/backend.native/tests/framework/permanentObjects/knlibrary.kt

@@ -0,0 +1,25 @@
+@file:OptIn(kotlin.ExperimentalStdlibApi::class)
+
+import kotlin.native.internal.GC
+import kotlin.native.internal.gc.GCInfo
+import kotlin.native.internal.isPermanent
+import kotlin.test.*
+
+private var _counter = 0
+
+object Permanent {
+    var counter
+        get() = _counter
+        set(value) {
+            _counter = value
+        }
+}
+
+fun assertIsPermanent() {
+    assertTrue(Permanent.isPermanent())
+}
+
+fun stableRefsCount(): Long {
+    GC.collect()
+    return GC.lastGCInfo!!.rootSet.stableReferences
+}

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

@@ -0,0 +1,24 @@
+import PermanentObjects
+
+func testPermanentObjects() throws {
+    PermanentObjects.KnlibraryKt.assertIsPermanent()
+    let stableRefsBefore = PermanentObjects.KnlibraryKt.stableRefsCount()
+    autoreleasepool {
+        for i in 0..<1000 {
+            PermanentObjects.Permanent().counter += 1
+        }
+    }
+    let stableRefsAfter = PermanentObjects.KnlibraryKt.stableRefsCount()
+    try assertEquals(actual: PermanentObjects.Permanent().counter, expected: 1000)
+    try assertEquals(actual: stableRefsAfter, expected: stableRefsBefore)
+}
+
+// -------- Execution of the test --------
+
+class TestTests : SimpleTestProvider {
+    override init() {
+        super.init()
+
+        test("permanentObjects", testPermanentObjects)
+    }
+}