Proposed targets to deprecate for 3.4

[Kazu Hirata]

Hi Zack and Nathanael,

> --- arch-obs-criteria.txt ---

This is a great piece of work.  Why don't we put this file somewhere
on our web site?  A obsoleted target list maintainer usually end up
receiving a lot of emails.  If we put up the file in public to have
people directly update the entries, that would alleviate his/her job
to some extent.  Certain entries like define_peephole or cc0 are
pretty easy to maintain even for those not familiar with each port.

Just a thought...

Kazu Hirata