Remove function visitor dimension check
Remove function visitor dimension check

We weren't visiting constraints on dimensions beyond the fourth,
probably because that used to be the limit on a buffer_t. Removed. Done
as a PR for testing in case I'm missing something.


Former-commit-id: 68765c56948760d13b343bd3783b217eec8e3db4
darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide