Description:
------------
I have a PHP production setup where errors are automatically reported to me via email, by using a custom error handler.

However, when PHP reaches it's memory limit the custom error handler is disabled. As a result, I may not be notified of OOM errors.

It would be nice if PHP did one of two things:
1) Emit an E_WARNING the first time the script reaches 99% (or something like that, maybe configurable) of memory_limit.
2) When the program reaches the memory limit the first time, add fx 1MB (perhaps user configurable) to the memory limit, emit an OOM E_WARNING, and let the custom error handler handle the error. The next time the memory limit is reached then really die.

I would prefer 1)

Reproduce code:
---------------
<?php
function custom_error_handler($error_code, $error_string, $filename, $line, $symbols) {
  die("This is the custom error handler");
}
set_error_handler('custom_error_handler');

$i = 0;
$a = Array();
while (true) {
  $a[$i] = $i++;
}
?>


Expected result:
----------------
It would be nice if my custom error handler was allowed to run.

Actual result:
--------------
t@t ~/php_oom> php test.php

Fatal error: Allowed memory size of 16777216 bytes exhausted (tried to allocate 35 bytes) in /home/thue/php_oom/test.php on line 10