Description:
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Allowed memory size problem when POSTing on a PHP script with 1.5MB data that turns out to be 8MB+ when PHP populates its internal variables ($_POST and so on).

This should be better documented in the manual I think, as the default post_max_size is 8M, the same as memory_limit (now I know memory_limit should be 128MB).

So this is really confusing, as:
- the script name is ?Unknown?
- post_max_size is too high for this type of error (if not using $_FILES) as memory_limit fires up first
- too much time spent on this :-(

Reproduce code:
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Run a POST request with enough data again any PHP script.

Expected result:
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At least the filename in the error (line should still be 0), such as:
PHP Fatal error:  Allowed memory size of 8388608 bytes exhausted (tried to allocate 1412991 bytes) in /path/to/my/script.php on line 0

Same thing for POST-max-size error would be great:
PHP Warning:  Unknown: POST Content-Length of 2250121 bytes exceeds the limit of 1048576 bytes in /path/to/my/script.php on line 0

Actual result:
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PHP Fatal error:  Allowed memory size of 8388608 bytes exhausted (tried to allocate 1412991 bytes) in Unknown on line 0
PHP Warning:  Unknown: POST Content-Length of 2250121 bytes exceeds the limit of 1048576 bytes in Unknown on line 0