Recent removal of the 'aux' field in tree_common

[Jan Hubicka]

> Diego Novillo <dnovillo@redhat.com> writes:
> 
> > Is the idea to remove the aux field for good?  If so, I'd like to
> > discuss ways of mapping mechanisms so that we can associate other
> > data structures to a tree.
> > 
> > Having the aux field is convenient because it's quick and simple.
> ...
> 
> One problem with the 'aux' field is that it is incompatible with PCH.
> For PCH, you really want every pointer in every structure to have one
> and only one type.  In particular, you don't want to have void *
> pointers.

I guess the aux field is used for temporary information only inside
the tree optimizer, so it is nonissue for PCH.

Honza Hubicka