Setup default values for type-safe bridges

#KT-9973 In Progress

compiler/testData/codegen/box/specialBuiltins/emptyStringMap.kt

@@ -0,0 +1,21 @@
+private object EmptyStringMap : Map<String, Nothing> {
+    override val size: Int get() = 0
+    override fun isEmpty(): Boolean = true
+
+    override fun containsKey(key: String): Boolean = false
+    override fun containsValue(value: Nothing): Boolean = false
+    override fun get(key: String): Nothing? = null
+    override val entries: Set<Map.Entry<String, Nothing>> get() = null!!
+    override val keys: Set<String> get() = null!!
+    override val values: Collection<Nothing> get() = null!!
+}
+
+fun box(): String {
+    val n = EmptyStringMap as Map<Any?, Any?>
+
+    if (n.get(null) != null) return "fail 1"
+    if (n.containsKey(null)) return "fail 2"
+    if (n.containsValue(null)) return "fail 3"
+
+    return "OK"
+}