Minor change to previous commit that causes the branches with undef values to be elided completely.
Minor change to previous commit that causes the branches with undef values to be elided completely.


Former-commit-id: 9aeaa7da8023c8cb2c4e10a903cc83aeed6ee9d5
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide