Move blackBoxFile() testData to box/ directory

Delete all test methods (and empty test classes), since they'll be
auto-generated

compiler/testData/codegen/box/extensionFunctions/kt606.kt

@@ -0,0 +1,29 @@
+package kt606
+
+//KT-606 wrong resolved call
+
+class StandardPipelineFactory(val config : ChannelPipeline.() -> Unit) : ChannelPipelineFactory {
+    override fun getPipeline() : ChannelPipeline {
+        val pipeline : ChannelPipeline = DefaultChannelPipeline()
+        pipeline.config()
+        return pipeline
+    }
+}
+
+trait ChannelPipeline  {
+  fun print(any: Any)
+}
+
+class DefaultChannelPipeline : ChannelPipeline {
+  override fun print(any: Any) = System.out?.println(any)
+
+}
+
+trait ChannelPipelineFactory {
+    fun getPipeline() : ChannelPipeline
+}
+
+fun box() : String {
+    StandardPipelineFactory({ print("OK") }).getPipeline()
+    return "OK"
+}