Merge r172073 from trunk to the 4.6 release branch, to fix two

Merge r172073 from trunk to the 4.6 release branch, to fix two
ambiguities between extensions and new C++0x functions.

Tested: bootstrap + make check-c++ on x86_64

libstdc++-v3/ChangeLog:

2011-04-06  Jeffrey Yasskin  <jyasskin@google.com>

	* include/ext/algorithm (is_sorted): In C++0x mode import from
	namespace std.
	* include/ext/numeric (iota): In C++0x mode import from
	namespace std.
	* testsuite/ext/is_sorted/cxx0x.cc: New.
	* testsuite/ext/iota/cxx0x.cc: New.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gcc-4_6-branch@172074 138bc75d-0d04-0410-961f-82ee72b054a4