Different parsing of `#` comment on PHP 8

[kukulich]

Describe the bug
The # comment produces different tokens on PHP 8

Code sample

<?php

#

PHP 7.4

array(2) {
  [0]=>
  array(8) {
    ["type"]=>
    string(10) "T_OPEN_TAG"
    ["code"]=>
    int(382)
    ["content"]=>
    string(6) "<?php
"
    ["line"]=>
    int(1)
    ["column"]=>
    int(1)
    ["length"]=>
    int(5)
    ["level"]=>
    int(0)
    ["conditions"]=>
    array(0) {
    }
  }
  [1]=>
  array(8) {
    ["type"]=>
    string(9) "T_COMMENT"
    ["code"]=>
    int(380)
    ["content"]=>
    string(2) "#
"
    ["line"]=>
    int(2)
    ["column"]=>
    int(1)
    ["length"]=>
    int(1)
    ["level"]=>
    int(0)
    ["conditions"]=>
    array(0) {
    }
  }
}

PHP 8

array(3) {
  [0]=>
  array(8) {
    ["type"]=>
    string(10) "T_OPEN_TAG"
    ["code"]=>
    int(390)
    ["content"]=>
    string(6) "<?php
"
    ["line"]=>
    int(1)
    ["column"]=>
    int(1)
    ["length"]=>
    int(5)
    ["level"]=>
    int(0)
    ["conditions"]=>
    array(0) {
    }
  }
  [1]=>
  array(8) {
    ["code"]=>
    int(388)
    ["type"]=>
    string(9) "T_COMMENT"
    ["content"]=>
    string(1) "#"
    ["line"]=>
    int(2)
    ["column"]=>
    int(1)
    ["length"]=>
    int(1)
    ["level"]=>
    int(0)
    ["conditions"]=>
    array(0) {
    }
  }
  [2]=>
  array(8) {
    ["type"]=>
    string(12) "T_WHITESPACE"
    ["code"]=>
    int(393)
    ["content"]=>
    string(1) "
"
    ["line"]=>
    int(2)
    ["column"]=>
    int(2)
    ["length"]=>
    int(0)
    ["level"]=>
    int(0)
    ["conditions"]=>
    array(0) {
    }
  }
}

[jrfnl]

Related to #3027 which didn't take hash comments into account.

I will submit a PR to fix this, though I have a niggling feeling that we may have to undo that at a later stage depending on what the final tokenization for attributes in PHP 8.0 will be.

[jrfnl]

PR #3072 should fix this.

[gsherwood]

I've merged in the PR from @jrfn (thanks again). Thanks also for the bug report.