Initial convolution test.
Initial convolution test.

Compiles to semi-sensible code. Doesn't (yet) produce expected results.


Former-commit-id: f8a8c69e66fcc70664f8bc9c7f9f11f589a3c029
Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide