[Mesa-dev] i965 use STD430 packing by default

[Timothy Arceri]

shared (the default) and packed layouts are decided by the implementation.
Currently we just pack them using the std140 layout. This change makes it so
we use the slightly more compact std430 layout on i965.

The number of changes in patch 4 is a little unfortunate however I decided this
was better than changing the type completely behind the scenes. Given the
complexity of the ifc linking/validation code I figured it would be better to
aviod adding to that confusion. Also I intent to switch gallium over to std430
which would mean once SNB is updated to work with this (I don't have the
hardware) we could drop most of patch 4 again.

This change should be pretty well covered by the CTS but I also have a few basic
piglit tests that I'll send out a bit later once I finish up the gallium support.