* tree.cc (_Rb_tree_increment, _Rb_tree_decrement,
_Rb_tree_rebalance_for_erase, _Rb_tree_black_count): Mark nothrow;
update uses of _Rb_tree_rotate_left, _Rb_tree_rotate_right.
(_Rb_tree_rotate_left, _Rb_tree_rotate_right): Make wrapper and break
out body to ...
(local_Rb_tree_rotate_left, local_Rb_tree_rotate_right): New static
functions.
* stl_tree.h (_Rb_tree_increment, _Rb_tree_decrement,
_Rb_tree_insert_and_rebalance, _Rb_tree_rebalance_for_erase,
_Rb_tree_black_count): Mark nothrow.
From-SVN: r146184