Function gl::GetTransformFeedbackVarying

pub unsafe fn GetTransformFeedbackVarying(program: GLuint,
                                          index: GLuint,
                                          bufSize: GLsizei,
                                          length: *mut GLsizei,
                                          size: *mut GLsizei,
                                          type_: *mut GLenum,
                                          name: *mut GLchar)

Fallbacks: GetTransformFeedbackVaryingEXT