Avoid unnecessary call to ParentRunner.createTestClass() for tests no…

…t annotated with @RunWith.

src/main/java/org/junit/internal/builders/JUnit4Builder.java

@@ -1,12 +1,12 @@
 package org.junit.internal.builders;
 
 import org.junit.runner.Runner;
-import org.junit.runners.BlockJUnit4ClassRunner;
+import org.junit.runners.JUnit4;
 import org.junit.runners.model.RunnerBuilder;
 
 public class JUnit4Builder extends RunnerBuilder {
     @Override
     public Runner runnerForClass(Class<?> testClass) throws Throwable {
-        return new BlockJUnit4ClassRunner(testClass);
+        return new JUnit4(testClass);
     }
-}
+}

src/main/java/org/junit/runners/JUnit4.java

@@ -1,6 +1,7 @@
 package org.junit.runners;
 
 import org.junit.runners.model.InitializationError;
+import org.junit.runners.model.TestClass;
 
 /**
  * Aliases the current default JUnit 4 class runner, for future-proofing. If
@@ -19,6 +20,6 @@ public final class JUnit4 extends BlockJUnit4ClassRunner {
      * Constructs a new instance of the default runner
      */
     public JUnit4(Class<?> klass) throws InitializationError {
-        super(klass);
+        super(new TestClass(klass));
     }
 }