As mentioned a few days ago, a very nice thing that we can do with 
tree-ssa is eliminating all the messy handling of postincrements and the 
pending postincrement chain; and a RTL code that I had just learnt 
about, QUEUED. :-)

~700 lines go away, and many comments like "the caller should have done 
so" and "the callee will do so", which is quite nice.

Unfortunately (but quite understandably), va_arg expanders are heavy 
users of {pre,post}{in,de}crements, which means that this patch has 
ramifications in backend code.  The obvious solution is to expand 
preincrements and predecrements manually, and for postincrements use 
(x+N)-N; of course the real solution would be to transition these 
backends to using gimplifiers for va_arg: these could well use the 
now-banned tree codes, but this is well above my abilities.

This patch bootstrapped/regtested all languages on i686-pc-linux-gnu.  I 
also built cc1 for c4x-elf, fr30-elf, iq2000-elf, mn10300-elf, m32r-elf, 
mips-elf, hppa-linux, i860-sysv4, s390-linux.

Ok for mainline?

Paolo