New assert in haifa-sched.c

[Eric Botcazou]

> I don't see the logic here.  It is certainly not that hard to fix the
> code to make this assertion trivial, simple loop through all insns in
> sched_init() will do it.

Yes, but apparently nobody is willing to do that at the moment so we'll need 
to kludge until then and add calls to recog_memoized when we stumble on insns 
that have not been recognized.  But our laziness shouldn't impact the user if 
we are confident that this cannot result in wrong code.

> There is a bug and it should get fixed rather than suppressed.

AFAICS nobody has submitted a real fix for this bug.  I'm ready to approve 
Adam's patch but only if the assertion is downgraded to ENABLE_CHECKING.

-- 
Eric Botcazou