Delegated implementations for properties and extension properties.

compiler/testData/ir/irText/classes/delegatedImplementationWithExplicitOverride.kt

@@ -0,0 +1,13 @@
+interface IFooBar {
+    fun foo()
+    fun bar()
+}
+
+object FooBarImpl : IFooBar {
+    override fun foo() {}
+    override fun bar() {}
+}
+
+class C : IFooBar by FooBarImpl {
+    override fun bar() {}
+}