Reverse order of std::swap_range and std::iter_swap

[jwellbelove]

There is an issue when compiling for a Genuino Zero.
It does not like the fact that the definition for std::iter_swap comes before std::swap_range (which uses it).
The order two functions should be swapped.

[mike-matera]

Thanks for the report. It works for me when I try to build. What version of Arduino are you using? Also, could you provide a sample sketch?