Description:
------------
Assignments which should otherwise evaluate to references of the l-value do not properly do so in some situations, but do in others.

Reproduce code:
---------------
1. echo ($x = 5)--;
2. echo ($x = Array(3))[0];
3. echo ($x = ($y = 3));

I presume this is also related:

4.
function foo(){ return Array(3); }
echo (foo())[0];

Expected result:
----------------
1. 4
2. 3
3. 3
4. 3

Actual result:
--------------
1. Parser chokes on T_DEC
2. Parser chokes on [
3. Works correctly, 3 is assigned to $x and $y and printed.
4. Parser chokes on [