check if abstract test class has non abstract inheritor -> its test methods are used

java/java-tests/testData/inspection/deadCode/junitAbstractClassWithInheritor/expected.xml

@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<problems/>

java/java-tests/testData/inspection/deadCode/junitAbstractClassWithInheritor/src/ChildTest.java

@@ -0,0 +1 @@
+public class ChildTest extends AbstractTest {}

java/java-tests/testData/inspection/deadCode/junitAbstractClassWithInheritor/src/Test.java

@@ -0,0 +1,4 @@
+public abstract class AbstractTest {
+  @org.junit.Test
+  public void testSmth() {}
+}