Add (failing) test that halide doesn’t clobber OpenGL state.
Add (failing) test that halide doesn’t clobber OpenGL state.

Sets the state to an arbitrary known value, calls halide, then checks the state.

kgnk/Halide,jiawen/Halide,jiawen/Halide,kgnk/Halide,psuriana/Halide,jiawen/Halide,ronen/Halide,psuriana/Halide,kgnk/Halide,psuriana/Halide,ronen/Halide,ronen/Halide,kgnk/Halide,psuriana/Halide,ronen/Halide,ronen/Halide,kgnk/Halide,ronen/Halide,jiawen/Halide,kgnk/Halide,ronen/Halide,jiawen/Halide,jiawen/Halide,kgnk/Halide,psuriana/Halide,psuriana/Halide,jiawen/Halide,psuriana/Halide,ronen/Halide,kgnk/Halide