[Mesa-dev] [PATCH V2 0/3] ARB_gpu_shader5 interpolateAt* plumbing

[Chris Forbes]

This series adds the driver-independent bits for the following new
builtin functions in ARB_gpu_shader5:

- interpolateAtCentroid
- interpolateAtOffset
- interpolateAtSample

Passes all the compiler piglits for these builtins.

Big changes from the RFC series from the other day:

- Don't abuse ir_var_mode_shader_in; add a new flag for it.
- Don't assume everyone wants lowering of interpolateAtSample.