Revert signature change in BDRU.registerWithGeneratedName

This change broke binary compatibility as evidenced by running
the greenhouse test suite and finding that Spring Integration's
AbstractConsumerEndpointParser.parseInternal fails with
NoSuchMethodError when trying to invoke.

org.springframework.beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionReaderUtils.java

@@ -166,7 +166,7 @@ public class BeanDefinitionReaderUtils {
 	 * for the given bean definition or the definition cannot be registered
 	 */
 	public static String registerWithGeneratedName(
-			BeanDefinition definition, BeanDefinitionRegistry registry)
+			AbstractBeanDefinition definition, BeanDefinitionRegistry registry)
 			throws BeanDefinitionStoreException {
 
 		String generatedName = generateBeanName(definition, registry, false);