[patch] Import iota and is_sorted from std to __gnu_cxx in C++0x mode. (issue4384043)

In C++0x mode, import iota and is_sorted from namespace std into namespace __gnu_cxx to avoid ambiguous call errors. copy_n would be a good candidate for this too, except it was standardized with a different return type. I think this is a candidate to backport to libstdc++-4.6.1. Tested:

Re: [patch] Import iota and is_sorted from std to __gnu_cxx in C++0x mode. (issue4384043)

Hi, I think this is a candidate to backport to libstdc++-4.6.1. Ok mainline and 4_6-branch if testing passes. Thanks, Paolo