Description:
------------
In 7.2.0, using two traits that define the same static property cause a fatal error. Only static properties are affected. 

I've put this up on https://3v4l.org/oi4ns to show the behaviour on different PHP versions.

I couldn't find this documented in the PHP 7.2.0 release notes / migration guide.


Test script:
---------------
https://3v4l.org/oi4ns

<?php

trait T1
{
	public static $prop1 = 1;
}

trait T2
{
	public static $prop1 = 1;
}

class Base
{
	use T1;
}

class Child extends base
{
	use T2;
}


Expected result:
----------------
Expected behaviour:

- no fatal errors, no warnings, code executes


Actual result:
--------------
Actual behaviour:

- fatal error: Fatal error: Base and T2 define the same property ($prop1) in the composition of Child. However, the definition differs and is considered incompatible. Class was composed in /in/oi4ns on line 18