[Piglit] [PATCH 0/5 v2] Add tests for NV_draw_buffers

[Ian Romanick]

Patches recently went to the mesa-dev list to add support for this
extension in OpenGL ES 2.0 contexts.  This patch series modifies the
existing desktop OpenGL fbo-drawbuffers to work with OpenGL ES 2.0
when NV_draw_buffers is available.

v2: Make the desktop GL version and the ES2 version of the test use
shaders.  The makes the test a lot more readable, but forces a
work-around for a stupid Mesa bug.  (Binding a user-defined attribute
to attribute 0 does not work.)