SSA implementation

[Richard Kenner]

    We will be contributing a dead-code elimination pass in the very near
    future that operates on the SSA form.  One big improvement is that
    this algorithm is a) very fast and b) can eliminate loops in things
    like:

  void f () { 
    int i;
    for (i = 0; i < 100; ++i)
      ;
  }

We could always have eliminated such loops, but as I understood it, we
chose not to under the assumption they were there for timing delay
purposes.  Has this policy chaged?