Description:
------------
In php 7.1.0 in changelog there is written that there were added additional parameter to unpack function:

unpack() function accepts an additional optional argument $offset.

But in php 7.1.0 the number of parameters and required parameters is both 2. In php 7.1.1 both returns 3

Test script:
---------------
$test = new ReflectionFunction("unpack");
echo $test->getNumberOfRequiredParameters();
echo $test->getNumberOfParameters();

Expected result:
----------------
For php 7.1.0:
2
3
For php 7.1.1:
2
3

Actual result:
--------------
For php 7.1.0:
2
2
For php 7.1.1:
3
3