glslparsertest: Fix handling of GL_GEOMETRY_VERTICES_OUT_ARB.

When testing geometry shaders, glslparsertest must set
GL_GEOMETRY_VERTICES_OUT_ARB before linking, since the default value
of this setting (0) is fairly useless.

Previously, we were accidentally passing the shader name to
glProgramParameteri() instead of the program name, causing spurious
errors.
Test that fast color clears are resolved even if front rendering intervenes.
Test a front buffer corner case: invalidate causes data loss.

Cc: Eric Anholt <eric@anholt.net>

v2: Move to spec/gl-1.0.  Add to all.tests.
Test interaction between fast color clears and glXSwapBuffers.
!UPSTREAM: Performance micro-benchmark for fast color clears.
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: start testing GS in/out types
WIP: fix shader_runner error reporting when vertex data included.
WIP: Basic test of GS input varyings
Geometry shaders: add a basic EndPrimitive() test.
WIP: large EndPrimitive test
shader_runner: Add missing newlines to error messages.

Certain shader error messages were missing newlines, leading to the
error message being concatenated on the same line with "PIGLIT:
{'result': 'fail' }".
Make shader_runner able to test new primitive types
!UPSTREAM: Start working on a function accuracy test
!UPSTREAM: more experimentation with function accuracy
!UPSTREAM: glx-fast-color-clear experiments
!UPSTREAM: read-after-swap

This works but I'm not convinced it's a good idea yet.

TODO:
- Discuss on mailing list.
!UPSTREAM: hacks
Front buffer rendering sanity test
Hacks