Following on from: https://gcc.gnu.org/ml/gcc-patches/2015-06/msg01066.html this series unifies the key hashing traits for hash_maps in all but one case (which needs to use the values rather than keys to represent deleted and empty entries).
It also consolidates the various tree, integer and string hashers so that there's only one copy of each. This series is a net reduction of 121 lines, despite using the more verbose out-of-class function definitions and having new copyright notices. The series linked above is a net reduction of 419 lines. Series bootstrapped & regression-tested on x86_64-linux-gnu. Also tested with config-list.mk. Thanks, Richard
