Generating stub methods for read-only map and entry.

compiler/testData/codegen/box/builtinStubMethods/MapEntry.kt

@@ -0,0 +1,15 @@
+class MyMapEntry<K, V>: Map.Entry<K, V> {
+    override fun hashCode(): Int = 0
+    override fun equals(other: Any?): Boolean = false
+    override fun getKey(): K = throw UnsupportedOperationException()
+    override fun getValue(): V = throw UnsupportedOperationException()
+}
+
+fun box(): String {
+    try {
+        (MyMapEntry<String, Int>() as MutableMap.MutableEntry<String, Int>).setValue(1)
+        throw AssertionError()
+    } catch (e: UnsupportedOperationException) {
+        return "OK"
+    }
+}