Class definitions should not be part of DiscouragedPHPFunctions warnings

[frankiejarrett]

This seems like a bug to me. You should be able to name your classes anything you want, especially within a namespace.

If you were going to run sniffs on class names (which I can't think of any use cases for) they'd be better off in their own DiscouragedPHPClasses sniff.

Consider the following test.php:

<?php

namespace Foo;

class System {
	// Things
}

class Serialize {
	// Things
}

And WordPress_Sniffs_PHP_DiscouragedPHPFunctionsSniff will throw:

FILE: test.php
----------------------------------------------------------------------
FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
----------------------------------------------------------------------
  5 | WARNING | system() found. PHP system calls are often disabled
    |         | by server admins.
  9 | WARNING | serialize() found. Serialized data has known
    |         | vulnerability problems with Object Injection. JSON is
    |         | generally a better approach for serializing data. See
    |         | https://www.owasp.org/index.php/PHP_Object_Injection
----------------------------------------------------------------------

[JDGrimes]

Yes, this is definitely a bug, the sniff needs to only flag function calls and not just any T_STRING. Adding T_CLASS to this list should fix the issue, I think.

[ocean90]

Related: #719