ToFirstComponent in wltransform.c uses PMarray, but AVIS_SSAASSIGN no longer valid

Bugzilla Link	588
Created on	Nov 08, 2009 17:20
Resolution	FIXED
Resolved on	Dec 11, 2009 17:30
Version	1.00beta
OS	Linux
Architecture	PC

Extended Description

Summary says it all.
wltransform in Phase 13 uses PMarray, but PM depends on presence of 
valid AVIS_SSAASSIGN. Unfortunately, the beginning of phase 13
removes SSA-ness.
apex/histgradeAKD.sac suffers from this problem, when compiled
with sac2c -extrema -nowlf -doawlf, in Build #16532, going 
whonose how far back in time.
I do not know if WLTR can safely be moved in front of USSA.
If so, then that may be an acceptable solution.
Now, the direct cause of the bug is that we have something like:
  bound2 = [ul];
  bound2' = bound2;
  z = with(... bound2')
So, we have to chase bound2' back to bound2 to find the N_array.
However, we are post-SSA, so this won't work.
It may be that we can merely insert a VP call "somewhat' earlier
in the phase, which would allow simplification of ToFirstComponent in 
WLTR.
Suggestions welcome.