Speeding up sched1

[Jeffrey A Law]

  In message < 19991107012830.A15561@cygnus.com >you write:
  > Probably true.  I could reorg flow such that they got 0 and n-1
  > respectively, and make n_basic_blocks += 2.  That would kinda
  > weird out things that check n_basic_blocks == 1 though...
Yea.  Eventually we're going to need to do it though.  But I haven't even
started to look at how many things are going to break.

  > I don't have a good feel for how to fix things.  What we have
  > at present is gonna break with Catherine's multiple entry points.
We're in no worse shape than before my change.  Previously we'd skip
the first block with a loop like
for (i = 1; i < n_basic_blocks; i++)
  {
     do something for block I
  }

jeff