[Piglit] [PATCH 0/4] Add simple GL_ARB_draw_instanced tests, v2

[Ian Romanick]

This is the patch set that I intended to send out in the first place.
The only change from the original is in patch 4/4.

 - draw-non-instanced.shader_test is changed to use gl_InstanceIDARB
   instead of gl_InstanceID.  It also has its requirements section
   updated, and the commented #version line is deleted.

 - instance-array-dereference.shader_test is changed to use / require
   GLSL 1.20.  It uses an initializer on a uniform, and that is
   functionality added in GLSL 1.20.

instance-array-dereference.shader_test hits essentially the same
functionality as draw-instanced.c, but it uses the shader-runner
framework.