OptIn for K/N identityHashCode() (#3693)

The function was made experimental as a part of efforts to stabilize Native stdlib.

Author: qurbonzoda

kotlinx-coroutines-core/native/src/Debug.kt

@@ -9,6 +9,7 @@ import kotlin.native.*
 
 internal actual val DEBUG: Boolean = false
 
+@OptIn(ExperimentalStdlibApi::class)
 internal actual val Any.hexAddress: String get() = identityHashCode().toUInt().toString(16)
 
 internal actual val Any.classSimpleName: String get() = this::class.simpleName ?: "Unknown"