Description:
------------
To reproduce:
1. Make a form that has a "file" input type.
2. Submit the form without a file (e.g. fill in the other fields).

(Using the PHP7 Vagrant box with git updated to the latest master branch.)

Test script:
---------------
<?php

if (!empty($_POST)) {
	var_dump($_POST);
}

?>


<form enctype="multipart/form-data" method="post">
	<p><input type="text" name="name">
	<p><input type="file" name="file">
	<p><input type="submit" value="Save">
</form>


Actual result:
--------------
A notice that no file was supplied.

Notice: No file uploaded in Unknown on line 0

A very old bug #32446 seems to imply this has happened before so it may be a regression.