Add support for clamping of color outputs to GS/TES
This is a step towards allowing higher GL versions of compat profile for NIR based gallium drivers. This allows iris to pass the vertex color clamping piglit tests for gs/tes.
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This is a step towards allowing higher GL versions of compat profile for NIR based gallium drivers. This allows iris to pass the vertex color clamping piglit tests for gs/tes.