enable u8/i8 for llvm 3.4 (because u8q/i8q use them)
enable u8/i8 for llvm 3.4 (because u8q/i8q use them)


Former-commit-id: bedbec38e70cb0c0351ed19266dbed81b38c0055
Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide