[Mesa-dev] V3 ARB_enhanced_layouts component qualifier support

[Timothy Arceri]

Most of this is just a resend.

The new patches are:

[PATCH 20/26] glsl: skip location and component packing validation on
[PATCH 21/26] glsl: don't try to eliminate unused patches with
[PATCH 22/26] glsl: include per-patch varyings when generating
[PATCH 23/26] glsl: add helper for comparing arrays in varying

Since V2 I discovered issues with per-patch outputs that some
of the above patches work around. There is also another existing issue
in Mesa were mixing explicit/implicit patch locations will result in
multiple varyings being assigned the same location. However I'd like
to fix all thse in a follow-up series. 

There are also updates to:

[PATCH 24/26] glsl: lower tessellation varyings packed with component

One notable change is that I've realised the tess packing pass doesn't
handle packing of different array types or arrays starting at different
locations. This is allowed by the spec but I'm throwing an error for
now when we come across these. I think eventually we should maybe just
pass the packing information down to the backend rather than trying to
shadow varyings but for now this pass is still more compliant than the
Nvidia blob which can't pack arrays in tess at all.