Enhance performance test

[Paolo Carlini]

On 11/04/2011 10:32 PM, François Dumont wrote:
> Hi
>
>     Here is a patch to enhance the performance test introduced 
> recently for hashtable. It shows more clearly the 41975 performance 
> issue. I also introduced a bench using unordered_set<string> so that 
> we have a tests involving a type with costlier hash functor than the 
> one used for int. And lastly the bench are run twice, with and without 
> hash code cached.
>
> 2011-11-04  François Dumont <fdumont@gcc.gnu.org>
>
>         * testsuite/performance/23_containers/insert_erase/41975.cc: Add
>         tests to check performance with or without cache of hash code 
> and with
>         string type that has a costlier hash functor than int type.
>
> Ok to commit ?
Looks Ok, but, as usual, watch overlong lines!

Paolo.