Make freezing stuff non-terminating TODO

kotlin-native/runtime/src/main/cpp/Atomic.cpp

@@ -176,6 +176,10 @@ KNativePtr Kotlin_AtomicNativePtr_get(KRef thiz) {
 }
 
 void Kotlin_AtomicReference_checkIfFrozen(KRef value) {
+    if (CurrentMemoryModel == MemoryModel::kExperimental) {
+        // TODO: Remove when freezing is implemented.
+        return;
+    }
     if (value != nullptr && !isPermanentOrFrozen(value)) {
         ThrowInvalidMutabilityException(value);
     }

kotlin-native/runtime/src/mm/cpp/Memory.cpp

@@ -95,6 +95,10 @@ void ObjHeader::destroyMetaObject(ObjHeader* object) {
     mm::ExtraObjectData::Uninstall(object);
 }
 
+ALWAYS_INLINE bool isPermanentOrFrozen(const ObjHeader* obj) {
+    return obj->permanent() || isFrozen(obj);
+}
+
 ALWAYS_INLINE bool isShareable(const ObjHeader* obj) {
     // TODO: Remove when legacy MM is gone.
     return true;

kotlin-native/runtime/src/mm/cpp/Stubs.cpp

@@ -8,21 +8,18 @@
 #include "KAssert.h"
 
 ALWAYS_INLINE bool isFrozen(const ObjHeader* obj) {
-    TODO();
-}
-
-ALWAYS_INLINE bool isPermanentOrFrozen(const ObjHeader* obj) {
-    TODO();
+    // TODO: Unimplemented
+    return false;
 }
 
 extern "C" {
 
 void MutationCheck(ObjHeader* obj) {
-    TODO();
+    // TODO: Unimplemented
 }
 
 void FreezeSubgraph(ObjHeader* obj) {
-    TODO();
+    // TODO: Unimplemented
 }
 
 void EnsureNeverFrozen(ObjHeader* obj) {