Fix missing mark of pure dims as pure.
Fix missing mark of pure dims as pure.


Former-commit-id: c923d58a3fcf1f4c878bbaaee14d9eae72f4183f
darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide