The mapping between bytecode offsets and source lines (lnotab) did not contain
an entry for the beginning of the loop.

Now it does, and the lnotab can be a bit larger:
in particular, several statements on the same line generate several entries.
However, this does not bother the settrace function, which will trigger only
one 'line' event.

The lnotab seems to be exactly the same as with python2.4.