Add MutableMap.remove(K, V) as built-in declaration

Use PlatformDependent annotation to guarantee it's only be available for JDK8
Also adjust type-safe bridges and mutable collection stubs generation

core/builtins/native/kotlin/Collections.kt

@@ -16,6 +16,8 @@
 
 package kotlin.collections
 
+import kotlin.internal.PlatformDependent
+
 /**
  * Classes that inherit from this interface can be represented as a sequence of elements that can
  * be iterated over.
@@ -350,6 +352,17 @@ public interface MutableMap<K, V> : Map<K, V> {
      */
     public fun remove(key: K): V?
 
+    /**
+     * Removes the entry for the specified key only if it is mapped to the specified value.
+     *
+     * @return true if entry was removed
+     */
+    @PlatformDependent
+    public fun remove(key: K, value: V): Boolean {
+        // See default implementation in JDK sources
+        return true
+    }
+
     // Bulk Modification Operations
     /**
      * Updates this map with key/value pairs from the specified map [from].