[RFC] Mesa package updates for sid and wheezy

[Jon Severinsson <jon@severinsson.net>]

I recently made a local package of mesa 8.0.4+git for some of my systems,
and while that package would not be suitable for testing, I believe some of
the patches I included would be of great benefit for wheezy, and I've
therefore prepared this series for your consideration.

Some notes on the content:

* The first patch is an upstream fix of a bug that only manifests with the
  experimental configure option "--enable-shared-glapi", which the current
  wheezy/sid package already have enabled.
* The second, fifth and sixth patch together enables building agains the
  shared llvm library instead of the static one. As several mesa libraries
  link with llvm, the savings are quite substantial. I measured a 33 MiB
  archive size reduction and a 91 MiB installed size reduction (not
  including *-dbg packages) for amd64, at the cost of a single 28 MiB
  dependancy. Note that this is already enabled in the debian-experimental
  branch.
* The fourth patch upgrades mesa to llvm 3.0. It's inclusion is optional,
  I just figgured that as 3.0 is the default llvm version in wheezy it would
  be slightly more likely to already be installed, as well as likely to be
  better maintained during the wheezy lifecyle.
* The seventh and eight patch together enables building shared versions of
  the dricore utility libraries. Unlike llvm, their use are constrained to
  the libgl1-mesa-dri package, so the savings aren't quite as stellar. I
  measured a 10 MiB archive size reduction and 13 MiB installed size
  reduction (not including the *-dbg package) for amd64, at no additional
  cost. Note that this is already enabled in the debian-experimental branch.
* The last patch just adds a recommends on libtxc-dxtn-s2tc0 in order to
  provide at least limited S3TC support out of the box.

Hope this series is of some use to you.

Best Regards
Jon Severinsson