Add comment on how to make types "known"
Add comment on how to make types "known"


Former-commit-id: 9b7af6f36848ac9bf8c8993735c10029ac4e56ec
Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide