Avoid warning on llvms < 3.5
Avoid warning on llvms < 3.5

Former-commit-id: adc7963e0a012348a7ac53e15cb259d97d7d847f
Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide