do_exit name clash

When using PHP4 using the Pike module, using die() causes the Pike process to exit. The reason for this is the function do_exit() which exists in both Pike and PHP4. The Pike version actually calls exit. I suggest renaming the PHP4 one to zend_do_exit or something. Since it's only used in one place, this should not be a problem. Let me know if this is OK. I have done the changes locally and can check them in if you don't mind. -- [ Below is a random fortune, which is unrelated to the above message. ] Q: What's the difference between a Mac and an Etch-a-Sketch? A: You don't have to shake the Mac to clear the screen.