[FIR-TEST] Add test with ambiguity produced by definitely not null types

compiler/fir/resolve/testData/resolve/problems/definitelyNotNullAmbiguity.kt

@@ -0,0 +1,21 @@
+// FILE: KtVisitor.java
+
+public class KtVisitor<R, D> {}
+
+// FILE: A.java
+
+public interface A {
+    public <R, D> R accept(@org.jetbrains.annotations.NotNull KtVisitor<R, D> visitor, D data)
+}
+
+// FILE: B.kt
+
+interface B : A {
+    override fun <R, D> accept(visitor: KtVisitor<R, D>, data: D): R
+}
+
+// FILE: main.kt
+
+fun test(visitor: KtVisitor<String, Unit>, element: B) {
+    element.<!AMBIGUITY!>accept<!>(visitor, Unit)
+}

compiler/fir/resolve/testData/resolve/problems/definitelyNotNullAmbiguity.txt

@@ -0,0 +1,9 @@
+FILE: B.kt
+    public abstract interface B : R|A| {
+        public abstract override fun <R, D> accept(visitor: R|KtVisitor<R, D>|, data: R|D|): R|R|
+
+    }
+FILE: main.kt
+    public final fun test(visitor: R|KtVisitor<kotlin/String, kotlin/Unit>|, element: R|B|): R|kotlin/Unit| {
+        R|<local>/element|.<Ambiguity: accept, [/B.accept, /A.accept]>#(R|<local>/visitor|, Q|kotlin/Unit|)
+    }

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsTestGenerated.java

@@ -873,6 +873,11 @@ public class FirDiagnosticsTestGenerated extends AbstractFirDiagnosticsTest {
             runTest("compiler/fir/resolve/testData/resolve/problems/asImports.kt");
         }
 
+        @TestMetadata("definitelyNotNullAmbiguity.kt")
+        public void testDefinitelyNotNullAmbiguity() throws Exception {
+            runTest("compiler/fir/resolve/testData/resolve/problems/definitelyNotNullAmbiguity.kt");
+        }
+
         @TestMetadata("invokeOfLambdaWithReceiver.kt")
         public void testInvokeOfLambdaWithReceiver() throws Exception {
             runTest("compiler/fir/resolve/testData/resolve/problems/invokeOfLambdaWithReceiver.kt");