Put the same conditional bracket around struct buffer_t that is used in generated code so Halide.h can be include in in the same file as a generated header.
Put the same conditional bracket around struct buffer_t that is used
in generated code so Halide.h can be include in in the same file as a
generated header.


Former-commit-id: bc2c432c8bc54f1cc582275ac6bf474ea9f361dd
darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide