PR libstdc++/22102 (insert as close to hint as possible)
	* include/bits/stl_tree.h (_Rb_tree<>::_M_insert_lower,
	_M_insert_equal_lower): New.
	(_M_insert_equal(iterator, const _Val&),
	_M_insert_equal(const_iterator, const _Val&)): Use the above.
	* docs/html/ext/howto.html: Add an entry for DR 233.
	* testsuite/23_containers/multiset/modifiers/insert/22102.cc: New.
	* testsuite/23_containers/multimap/modifiers/insert/22102.cc: New.

	* testsuite/23_containers/set/insert/: Move...
	* testsuite/23_containers/set/modifiers/insert/: ...here.
	* testsuite/23_containers/map/insert/: Move...
	* testsuite/23_containers/map/modifiers/insert/: ...here.
	* testsuite/23_containers/multiset/insert/: Move...
	* testsuite/23_containers/multiset/modifiers/insert/: ...here.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@109473 138bc75d-0d04-0410-961f-82ee72b054a4