Description:
------------
I was testing a for loop with incrementing alpha characters.  For example, looping through a-z and printing those characters.  It does not seem to work as expected.

Reproduce code:
---------------
Ex 1:

for ($i = 'a'; $i <= 'z'; $i++) {
	echo $i;
}

Ex 2:

for ($i = 'a'; $i < 'z'; $i++) {
	echo $i;
}

Ex 3:

for ($i = 'a'; $i < 'aa'; $i++) {
	echo $i;
}

Expected result:
----------------
Ex 1:   Print a-z.

Ex 2:   Print a-y.

Ex 3:   Print a-z.

Actual result:
--------------
Ex1 loops through to 'yz' and does not work as expected.
Ex2 loops through to 'z', which is expected.
Ex3 dies after the first iteration and only prints 'a'.

I think this is an odd behavior.  The < operator works as expected in this example but the <= operator does not.  It doesn't seem like a consistent behavior.  If I can remember correctly, I was able to get this to work on an earlier version sometime ago.