more ia32 bugs (unrolling)

[Jeffrey A Law]

  In message < 37707D5F.84F1B9AD@knmi.nl >you write:
  > Yep, it also probably has nothing to do with loop unrolling (I got the
  > same error yesterday when trying an ordinary bootstrap, which uses flags
  > -O2 -g).  Unfortunately, I was too tired to track it down; I agree that
  > the real error must be that the JUMP_LABEL is null; at least, it doesn't
  > seem like a useful construct to me: a jump without a label.
Just to clarify -- there are cases where a jump can have a null JUMP_LABEL
(consider a table jump, or a return).

But for any normal conditional or unconditional jump we should have
a suitable JUMP_LABEL.  And in Mike's example all I saw were normal jumps.

jeff