I think, unless you are doing a project from scratch and disconnected
from the rest of the world, that Lua should be compiled with this
option, which probably doesn't harm anything.
I beg to differ. The new (5.1) behaviour is a lot simpler to
understand and to implement. IMHO the Lua authors' decision
is right and the old behaviour should go.
Just deprecating it in the docs and silently leaving it in,
means it never goes away. We've seen that with 'for x in table',
which was deprecated in the 5.0 docs. But the complaints
started just recently when one of the 5.1-work versions
finally dropped it (i.e. a few years later).
