Places where we can optimize PHP
--------------------------------

Easy
- Fix auto_globals_jit - I don't actually think this works at all right now.  
- Make ap_add_common_vars and ap_add_cgi_vars part of the server jit and
  we might be able to come up with a faster implementation of ap_add_common_vars.
  One that doesn't need to do a qsort with a strcasecmp cmp function on each
  and every request.
- zend_cleanup_function_data is by far the most called function in the engine.  And
  all it does is:

    if (function->type == ZEND_USER_FUNCTION) {
         zend_cleanup_op_array_data((zend_op_array *) function);
    }

Hard
- Go through and clean up cache lines in the executor


Investigate
- Is doing a table_get(subprocess_env, "HTTP_COOKIE") really the fastest way
  to check if we have a cookie on a request?  table_gets are expensive and
  we do this one on every request whether or not there is a cookie.
- Shortcut zend_ini_deactivate