arb_shader_texture_lod-texgradcube: Test explicit derivatives for cube maps

Similar to arb_shader_texture_lod-texgrad, but using cube maps instead.
Given the somewhat undefined behavior of explicit gradients with cube
maps, the main purpose of the test is really to test that those work at
all, as there doesn't seem to be any other test covering this.
That said, drivers which simply drop explicit derivatives on the floor
(like softpipe) pass this perfectly as it simply compares implicit vs.
explicit behavior (which, given the fuzzy specification, might not be
really required to be the same here, though given the chosen values, that
is the major axis derivatives being zero, it might seem like a reasonable
assumption).
I guess something which would also test that the implementation is really
using explicit derivatives instead of implicit ones would also be desirable,
but I'll leave that for now, I couldn't really come up with something.

Reviewed-by: Brian Paul <brianp@vmware.com>
lodbias: increase window size to fix test on Windows

Before, the 96x96 window got bumped up to 116x96 by Windows and we
saw a "Got spurious window resize in automatic run" message and the
test reported "warn".

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
arb_sampler_objects: use default window size to fix Windows run

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
arb_shader_objects: use default window size to fix Windows run

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
arb_framebuffer_object: use default window size to fix Windows run

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
arb_vertex_buffer_object: use default window size to fix Windows run

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
gl-1.0: use default window size to fix Windows run

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
draw-pixels: whitespace fixes, remove unneeded parenthesis

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
draw-pixels: display results when there's a failure

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
draw-pixels: use better test values

As it was, many of the generated / expected pixel values were all
zeros.  Use better values that actually fit in the given datatype.

For example, we were trying to store "0x23 << (6 - j)" in a GLbyte.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
draw-pixels: use default window size, for Windows

And set the pixel unpack alignment to 1 so that we don't fail if
the window width isn't a multiple of four.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Test interaction of primitive restart and transform feedback.
Test that transform feedback works with non-flat integers.

Commit 0fac0a6 (Modify tests for error checking on "flat" keyword to
match updated specs) adopted the GLSL 1.50 rules for "flat" varyings
for all desktop GL tests (the rationale was that this change likely
reflects a bug fix rather than a deliberate behavioural difference).

The GLSL 1.50 rules allow a vertex shader output to be a non-flat
integer provided that it isn't consumed by the fragment shader.  In
particular, this means that a non-flat integer may be used with
transform feedback.

This test verifies that transform feedback works correctly for all
integral types, even if they are not declared as "flat".
util: Create generic piglit_draw_rect() functions.  TODO: rework.

This patch adds the following functions to piglit-util-gl-common:
- piglit_draw_rect_generic
- piglit_draw_rect_back_generic
- piglit_draw_rect_z_generic
- piglit_draw_rect_tex_generic

These functions are similar to corresponding functions without the
"_generic" suffix, except that instead of delivering vertex position
and texture coordinates to the vertex shader using glVertexPointer()
and glTexCoordPointer(), they deliver to the generic attributes
PIGLIT_ATTRIB_POS and PIGLIT_ATTRIB_TEX.  These functions use VBO's
and VAO's when available, so they may be used when testing core
contexts.

These functions also work with compatibility contexts and with all
GLES versions.  Since GLES1 doesn't support generic vertex attributes,
we fall back to using glVertexPointer() and glTexCoordPointer() in the
GLES1 case.

When building GLES tests, the behaviour of the new _generic functions
is for all intents and purposes the same as that of the pre-existing
non-generic functions.  So to avoid code duplication, the non-generic
functions simply call their generic equivalents in GLES builds.
WIP: primitive restart draw mode test

TODO: improve initial commentary