Dereferencing an array in foreach unwraps the reference

Description

The following code (https://3v4l.org/8QBeN):

<?php

$a = [1]; 
foreach ((isset($a["key"]) ? [&$a["key"]] : [&$a])[0] as &$v) {
    var_dump($a);
    $v++;
}
var_dump($a);

Resulted in this output:

array(1) {
  [0]=>
  int(1)
}
array(1) {
  [0]=>
  int(1)
}

But I expected this output instead:

array(1) {
  [0]=>
  &int(1)
}
array(1) {
  [0]=>
  &int(2)
}

In PHP 7.2 and before, the output was as expected. Today it's required to use an explicit variable to preserve the reference.

PHP Version

PHP 7.3.0 - master

Operating System

No response

Start with the PHP reproducer linked in the issue and compare its behavior between PHP 7.2 and the reported PHP 7.3 version. Investigate how the foreach reference is handled when iterating over the conditional array expression. Done means the reference is preserved and the output matches the expected result, without requiring an explicit temporary variable.