[Mesa-dev] ARB_enhanced_layouts tranform feedback layouts

[Timothy Arceri]

This series adds support for the xfb_* layout qualifiers and API
support for querying them. It applies on top of my component 
packing series https://patchwork.freedesktop.org/series/3897/ but
can likely be rebased without it if this get reviewed first.

Most piglit test have been pushed to master. I have just sent three
more execution tests related to this series: 
https://patchwork.freedesktop.org/series/4465/

I also used the xfb tests from the GL CTS to test during development
which was helpful. All the CTS tests mostly pass now except for
some with issues outside of the scope of this series e.g. ';' on
a line by itself, unsized out block in TES, TCS without a TES, etc

Note the enhanced layouts CTS tests are in git but not in latest
tarball release.

This series can be found here:

https://github.com/tarceri/Mesa_arrays_of_arrays.git xfb_qualifiers8