Generate proper GLSL code for vector selects
Generate proper GLSL code for vector selects


Former-commit-id: 948c5eaef2a1d9c135c0063a8546238f5c705352
Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide