Extract Function: Add test data

idea/testData/refactoring/extractFunction/parameters/extractThis/implicitThisInExtension.kt.after

@@ -0,0 +1,10 @@
+class Z(val a: Int)
+
+// NEXT_SIBLING:
+fun Z.i(): Int {
+    return a
+}
+
+fun Z.foo(): Int {
+    return i() + 1
+}