[Mesa-dev] V4 ARB_enhanced_layouts packing support for i965 Gen6+

[Timothy Arceri]

V4:
- add vec4 backend support and enable for Gen6+

V3:
- Rewrite patch 9 (add support for packing arrays) to not add
hacks to the type_size() functions.
- Add packing support for the load_output intrinsics (patch 12)
- Add glsl_dvec_type() helper (patch 8)

V2:
- validation fixes patches 1-2
- added support for packing doubles now that explicit location
 fixes have landed.
- fix various issues with intel debug output with new COMPONENT const index.

This adds component packing support for Gen6+.

Series can be found in my component_packing_gen6+ branch:

https://github.com/tarceri/Mesa_arrays_of_arrays.git