lambda: do not mark cast redundant when functional interface won't be found otherwise

java/java-tests/testData/inspection/redundantCast/lambda/ExpectedSupertype/expected.xml

@@ -0,0 +1,3 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems>
+</problems>

java/java-tests/testData/inspection/redundantCast/lambda/ExpectedSupertype/src/Test.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2000-2012 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+public class Test {
+  interface I {
+  }
+
+  interface Bar extends I {
+    int compare(String o1, String o2);
+  }
+
+  {
+    I bar2 = (Bar) (o1, o2) -> 0;
+    g((Bar) (o1, o2) -> 0);
+    ((Bar) (o1, o2) -> 0).getClass();
+  }
+
+  void g(I i){}
+}

java/java-tests/testSrc/com/intellij/codeInspection/RedundantCast18Test.java

@@ -33,6 +33,7 @@ public class RedundantCast18Test extends InspectionTestCase {
   }
 
   public void testLambdaContext() throws Exception { doTest(); }
+  public void testExpectedSupertype() throws Exception { doTest(); }
 
   protected Sdk getTestProjectSdk() {
     Sdk sdk = JavaSdkImpl.getMockJdk17();