Ollie Wild  <aaw@google.com>

	* include/bits/hashtable.h
	(_Hashtable<>_M_insert_multi_node(hash_code, node_type*)): New.
	(_Hashtable<>_M_insert(_Args&&, false_type)): Use latter.
	(_Hashtable<>::_M_emplace(false_type, _Args&&...)): Likewise.
	(_Hashtable<>::_M_insert_bucket): Replace by ...
	(_Hashtable<>::_M_insert_unique_node(size_type, hash_code, node_type*)):
	... this, new.
	(_Hashtable<>::_M_insert(_Args&&, true_type)): Use latter.
	(_Hashtable<>::_M_emplace(true_type, _Args&&...)): Likewise.
	* include/bits/hashtable_policy.h (_Map_base<>::operator[]): Use
	latter, emplace the value_type rather than insert.
	* include/std/unordered_map: Include tuple.
	* include/std/unordered_set: Likewise.
	* testsuite/util/testsuite_counter_type.h: New.
	* testsuite/23_containers/unordered_map/operators/2.cc: New.

Co-Authored-By: Ollie Wild <aaw@google.com>

From-SVN: r190355