no_new_pseudos

[Paolo Bonzini]

> I am going to argue that it was a bug that we did not allow new
> pseudos after flow had ran.  And that we should have always allowed
> pseudos before the register allocator.  Since flow was so broken, we
> could not, we added the hack no_new_pseudos get around that problem.
> Now we are saying it is a nice abstraction but I am saying this
> abstraction should never have happened in the first place.  We now
> have a better compiler due to the removal of the hack.

The bad abstraction was causing quirks in *when* no_new_pseudos was set 
to 1.  But no_new_pseudos is a good abstraction in itself, people are 
arguing on whether it is a better abstraction as "reload_in_progress || 
reload_completed".

Paolo