Deduction guides for associative containers, debug mode deduction guide fixes.

Deduction guides for associative containers, debug mode deduction guide fixes.

* include/bits/stl_iterator.h (__iter_key_t)
(__iter_val_t, __iter_to_alloc_t): New.
* include/bits/stl_map.h: Add deduction guides.
* include/bits/stl_multimap.h: Likewise.
* include/bits/stl_multiset.h: Likewise.
* include/bits/stl_set.h: Likewise.
* include/bits/unordered_map.h: Likewise.
* include/bits/unordered_set.h: Likewise.
* include/debug/deque: Likewise.
* include/debug/forward_list: Likewise.
* include/debug/list: Likewise.
* include/debug/map.h: Likewise.
* include/debug/multimap.h: Likewise.
* include/debug/multiset.h: Likewise.
* include/debug/set.h: Likewise.
* include/debug/unordered_map: Likewise.
* include/debug/unordered_set: Likewise.
* include/debug/vector: Likewise.
* testsuite/23_containers/map/cons/deduction.cc: New.
* testsuite/23_containers/multimap/cons/deduction.cc: Likewise.
* testsuite/23_containers/multiset/cons/deduction.cc: Likewise.
* testsuite/23_containers/set/cons/deduction.cc: Likewise.
* testsuite/23_containers/unordered_map/cons/deduction.cc: Likewise.
* testsuite/23_containers/unordered_multimap/cons/deduction.cc:
Likewise.
* testsuite/23_containers/unordered_multiset/cons/deduction.cc:
Likewise.
* testsuite/23_containers/unordered_set/cons/deduction.cc: Likewise.

From-SVN: r254113