Passing in start to the benchmark function

updated_run_bench2.swift

let time11 = CFAbsoluteTimeGetCurrent()
for i in 0..<iterations {
  let result = flatuseStruct(outputData, start:i)
  assert(result == 8644311666 + Int(i))
  total2 = total2 + UInt64(result)
}
let time12 = CFAbsoluteTimeGetCurrent()

func flatuseStruct(buffer : UnsafePointer<UInt8>, start : UInt) -> Int
{
    var sum:Int = Int(start)
    
    // this struct or copies of it are only valid as long as pointer
    // to the underlying data is valid
    // should use createInstance() for a long-term usable mutable object instance
    // if needed, but the struct interface is good for lazy stream processing
    var foobarcontainer = FooBarContainer.Fast(buffer)
    
    sum = sum + Int(foobarcontainer.location!.count)
    sum = sum + Int(foobarcontainer.fruit!.rawValue)
    sum = sum + (foobarcontainer.initialized ? 1 : 0)
    let list = foobarcontainer.list
    for i in 0..<list.count {
        let foobar = list[i]!
        sum = sum + Int(foobar.name!.count)
        sum = sum + Int(foobar.postfix)
        sum = sum + Int(foobar.rating)

        let bar = foobar.sibling!
        
        sum = sum + Int(bar.ratio)
        sum = sum + Int(bar.size)
        sum = sum + Int(bar.time)
        
        let foo = bar.parent
        sum = sum + Int(foo.count)
        sum = sum + Int(foo.i_d)
        sum = sum + Int(foo.length)
        sum = sum + Int(foo.prefix)
    }
    return sum
}