Turn on CXX11 for the nightly builds
Turn on CXX11 for the nightly builds


Former-commit-id: 29b231d7dd0387a7522a60c2ad2f2371fa078ebe
Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide