[erlang-patches] Add dict:is_empty/1 and orddict:is_empty/1

[Magnus Henoch]

This patch adds the functions dict:is_empty/1 and orddict:is_empty/1.
For dict, comparing the size against 0 runs in constant time, but not
for orddict.  My new functions are an attempt to relieve users from
having to know such implementation details.

git fetch git://github.com/legoscia/otp.git dict_orddict_is_empty

https://github.com/legoscia/otp/compare/erlang:master...legoscia:dict_orddict_is_empty
https://github.com/legoscia/otp/compare/erlang:master...legoscia:dict_orddict_is_empty.patch

Regards,
Magnus