There are different unit-tests file generated containing lists of tests the test-runner.sh should run. Running run-tests.sh read the unit-tests in the current directory, which is inconvenient to do when using meson.
As with fixed pipelines, we require the use of the GLSL pipeline in mutter, and no point in supporting ARBfp anyway.
We require being able to use shaders so stop supporting a pipeline that wouldn't work to begin with.
