Description:
------------
ReflectionClass::isInstantiable() returns true for abstract classes. Of course, subsequent call to ReflectionClass::newInstance() fails. Please note: this is not the same as bug #28895 (which claims to be solved) - that bug submitter stressed that isAbstract always returns false. In this case, isAbstract returns true, but the isInstantiable also returns true.

Reproduce code:
---------------
<?

abstract class X {}

$rc = new ReflectionClass('X');
echo $rc->isAbstract() ? 'yes' : 'no', "\n";
if($rc->isInstantiable()) {
  echo "Class X is instantiable";
  $x = $rc->newInstance();
} else {
  echo "Cannot instantiate abstract class";
}

?>

Expected result:
----------------
yes
Cannot instantiate abstract class

Actual result:
--------------
yes
Class X is instantiable
Fatal error: Cannot instantiate abstract class X in /path/to/abstract.php on line 9