Description:
------------
If interface define any constants, then it's not possible (due to error) implement this interface in any class and extend any other class with this interface.

Reproduce code:
---------------
interface iA {

    const cA = 'const of iA';
}

class A implements iA {
}

class B extends A implements iA {
}

$b = new B();
echo iA::cA;
echo A::cA;
echo B::cA;

----- Another example -----

interface iA {

    const cA = 'const of iA';
}

class A implements iA {
}

interface iB extends iA {
}

class B extends A implements iB {
}

$b = new B();
echo iA::cA;
echo A::cA;
echo iB::cA;
echo B::cA;

Expected result:
----------------
const of iA
const of iA
const of iA

----- Another example -----

const of iA
const of iA
const of iA
const of iA

Actual result:
--------------
Fatal error: Cannot inherit previously-inherited constant cA from interface iA

----- Another example -----

Fatal error: Cannot inherit previously-inherited constant cA from interface iB