Add a test from KT-51950

compiler/testData/codegen/boxInline/anonymousObject/kt51950.kt

@@ -0,0 +1,24 @@
+// FILE: 1.kt
+interface Service {
+    fun send(message: String): String
+}
+
+inline fun Service.decorate(crossinline decorate: (Service) -> Service): Service =
+    object : Service by decorate(this) {}
+
+inline fun Service.transformMessage(crossinline transform: (String) -> String) =
+    decorate { service ->
+        object : Service {
+            override fun send(message: String): String =
+                service.send(transform(message))
+        }
+    }
+
+// FILE: 2.kt
+fun Service.append(suffix: String): Service =
+    transformMessage { it + suffix }
+
+fun box(): String =
+    object : Service {
+        override fun send(message: String): String = message
+    }.append("K").send("O")