Branch created for PR46489 (target macro elimination from frontends / tree optimizers)

[Joern Rennecke]

I have created the branch:
svn://gcc.gnu.org/svn/gcc/branches/pr46489-20101217-branch
to continue working on PR46489 while trunk is in slush / freeze mode.

The branch does not use the usual distributed ChangeLog scheme, but a single
ChangeLog.46489 in
svn://gcc.gnu.org/svn/gcc/branches/pr46489-20101217-branch/gcc that has
entries like for a patch submission.  That keep our options open to
either review the branch as a whole, or to convert the check-ins back
into patches and submit them when 4.7 phase 1 opens.

Yesterday I checked in two of the still unreviewed patches I had posted
previously on gcc-patches.

As the goal is no longer inclusion in 4.6 phase 3, but but 4.7 phase 1 or 2,
it now makes sense to look beyond the issue of front-end instability, and
also include further macro->hook conversions that make the design more
consistent.

In that spirit, I've checked a patch into the branch today to hookize
INIT_CUMULATIVE_ARGS and its two variants into a single hook.

Is there sufficient interest to post the branch patches to gcc-patches  
as I go?

FWIW my current contract under which I do this work ends at the end of
December, so I might not have much time to discuss the patches afterwards.