Add a test for the warning about parallel for loops of size one
Add a test for the warning about parallel for loops of size one


Former-commit-id: c38732b7ff4d5b3bdfbbbd5cbc9175ab09d079fc
darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide