update: warning suppression on Any (#5216)

Author: danil-pavlov

docs/topics/jvm/java-interop.md

@@ -687,10 +687,46 @@ so to make other members of `java.lang.Object` available, Kotlin uses [extension
 ### wait()/notify()
 
 Methods `wait()` and `notify()` are not available on references of type `Any`. Their usage is generally discouraged in
-favor of `java.util.concurrent`. If you really need to call these methods, you can cast to `java.lang.Object`:
+favor of `java.util.concurrent`.
+
+If you have to call these methods, cast to `java.lang.Object` and suppress the warning:
 
 ```kotlin
-(foo as java.lang.Object).wait()
+import java.util.LinkedList
+
+class SimpleBlockingQueue<T>(private val capacity: Int) {
+    private val queue = LinkedList<T>()
+
+    // java.lang.Object is used specifically to access wait() and notify()
+    // In Kotlin, the standard 'Any' type does not expose these methods.
+    @Suppress("PLATFORM_CLASS_MAPPED_TO_KOTLIN")
+    private val lock = Object()
+
+    fun put(item: T) {
+        synchronized(lock) {
+            while (queue.size >= capacity) {
+                lock.wait()
+            }
+            queue.add(item)
+            println("Produced: $item")
+
+            lock.notifyAll()
+        }
+    }
+
+    fun take(): T {
+        synchronized(lock) {
+            while (queue.isEmpty()) {
+                lock.wait()
+            }
+            val item = queue.removeFirst()
+            println("Consumed: $item")
+
+            lock.notifyAll()
+            return item
+        }
+    }
+}
 ```
 
 ### getClass()