[2.0] Fix Fatal errors in unused classes that crash the testsuite when running...

[2.0] Fix Fatal errors in unused classes that crash the testsuite when running PHPUnit with coverage-whitelisting of complete Doctrine directory.

lib/Doctrine/ORM/Persisters/ElementCollectionPersister.php

@@ -27,7 +27,7 @@ namespace Doctrine\ORM\Persisters;
  * @author robo
  * @todo Implementation once support for collections of basic elements (i.e. strings) is added.
  */
-class ElementCollectionPersister extends AbstractCollectionPersister
+abstract class ElementCollectionPersister extends AbstractCollectionPersister
 {
     //put your code here
 }
\ No newline at end of file

lib/Doctrine/ORM/Persisters/UnionSubclassPersister.php

@@ -2,7 +2,7 @@
 
 namespace Doctrine\ORM\Persisters;
 
-class UnionSubclassPersister extends AbstractEntityPersister
+class UnionSubclassPersister extends StandardEntityPersister
 {
     
 }
\ No newline at end of file