It previously only worked when the key and value types were
both 4 byte integers. We now have a use case for a non trivial
value type, so we need to extend it to support arbitrary value
types, which means templatizing it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327647 91177308-0d34-0410-b5e6-96231b3b80d8