Remove a constexpr for msvc 2013
Remove a constexpr for msvc 2013


Former-commit-id: a4d3b8b81658dbfedbd237348797aa7feb8c4d64
darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide