Prefix more error messages with GLSL to make clear where they are coming from
Prefix more error messages with GLSL to make clear where they are coming from


Former-commit-id: c127ad89414fe79938e87a74b4924aa97e96b185
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide