Add workarounds to enable HVX codegen.
Add workarounds to enable HVX codegen.


Former-commit-id: c8590db061e8abe49444920d108a4308d8b2dfd7
darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide