new inference: most specific with same functional interface presence

(cherry picked from commit f05ae78f4cfd030258264d717d7522ab0930d9a5)

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/mostSpecific/MostSpecificForSameFunctionalTypes.java

@@ -0,0 +1,33 @@
+abstract class HighlightTestInfo {
+  protected final String[] filePaths;
+  public HighlightTestInfo(Disposable <warning descr="Parameter 'buf' is never used">buf</warning>, String... filePaths) {
+    this.filePaths = filePaths;
+  }
+
+  protected abstract HighlightTestInfo doTest();
+}
+
+class StreamMain {
+  private Disposable <warning descr="Private field 'testRootDisposable' is never assigned">testRootDisposable</warning>;
+
+  public HighlightTestInfo testFile(String... filePath) {
+    return new HighlightTestInfo(getTestRootDisposable(), filePath) {
+      public HighlightTestInfo doTest() {
+        return this;
+      }
+    };
+  }
+
+  public Disposable getTestRootDisposable() {
+    return testRootDisposable;
+  }
+}
+
+interface Disposable {
+  void dispose();
+
+  interface Parent extends Disposable {
+    void beforeTreeDispose();
+  }
+
+}