[FIR-TEST] Add new testdata generated after changes in previous commit

compiler/testData/diagnostics/tests/operatorsOverloading/IteratorAmbiguity.fir.kt

@@ -0,0 +1,27 @@
+//KT-1821 Write test for ITERATOR_AMBIGUITY diagnostic
+
+interface MyCollectionInterface {
+}
+
+interface MyAnotherCollectionInterface {
+}
+
+class MyCollection : MyCollectionInterface, MyAnotherCollectionInterface {
+}
+
+fun MyCollectionInterface.iterator() = MyIterator()
+
+fun MyAnotherCollectionInterface.iterator() = MyIterator()
+
+class MyIterator {
+    fun next() : MyElement = MyElement()
+    fun hasNext() = true
+}
+
+class MyElement
+
+fun test1(collection: MyCollection) {
+    collection.<!AMBIGUITY!>iterator<!>()
+    <!AMBIGUITY, UNRESOLVED_REFERENCE, UNRESOLVED_REFERENCE!>for (element in collection) {
+    }<!>
+}