Fix #65108 (is_callable() triggers Fatal Error)

We have to check if the fcall info cache contains a pointer if we
use __call, otherwise we endup in a static lookup.
Merge branch 'PHP-5.5'

* PHP-5.5:
  Fix #65108 (is_callable() triggers Fatal Error)
Notify doc team BEFORE we release
Merge branch 'PHP-5.5'

* PHP-5.5:
  Notify doc team BEFORE we release
Fixed bug (is_callable() triggers Fatal Error)

This bug is also exists in 5.4, and previous fix by dsp is not complete
for __callStatic stituation, see test script
Merge branch 'PHP-5.4' into PHP-5.5

Conflicts:
	Zend/zend_API.c
Merge branch 'PHP-5.5' of git.php.net:php-src into PHP-5.5
Merge branch 'PHP-5.5'