Variables in docblock not highlighted

[CupOfTea696]

Description

Variables in PHP docblock aren't marked as .syntax--parameter .syntax--variable.

Steps to Reproduce

1. Open or create a PHP file
2. Write a docblock for a function or method with parameters

Edit by @rsese, adding snippet for easy copy/paste

<?php

/**
 * hello world
 *
 * @param string $abstract
 * @param \Closure|string|null $concrete
 * @return void
 */
public function singleton($abstract, $concrete = null) {
  return $this->bind($abstract, $concrete, true);
}

Expected behavior: Parameter names are highlighted

Actual behavior: Parameter names are seen as text

Reproduces how often: Always

Screenshots

[rsese]

Thanks for the report, reproduced with 1.34.0 on macOS 10.12.6.