[Piglit] [PATCH] New testsuite for ARB_color_buffer_float (v2)

[Luca Barbieri]

Yet another correction: the alpha test is performed after conversion
to the target format and polygon smoothing seems to be unavailable at
least on recent non-FireGL/Quadro cards.

So on cards without polygon smoothing, it seems impossible to tell
whether or not they clamp fragment colors on fixed point buffers,
since that is indistinguishable from the clamp done before blending or
when writing if blending is disabled.