This patch fixes a bug whereby the Python stack was not correctly reset if
there was a break/continue statement in the else black of an optimised
for-range loop.

For example, in the following code the "j" variable from the inner for loop
was not being popped off the Python stack:

    for i in range(4):
        for j in range(4):
            pass
        else:
            continue

This is now fixed with this patch.