[PATCH] benchtests: Add sinf traces

[Wilco Dijkstra]

Hi Adhemerval,

> Ok we are on the same page then.  The main problem is for some benchmark there a *lot* of
> sincos calls, so I will need to add some strategy to pull a representative range from
> the trace.

So what I did at the time was replay the trace in blocks of N and time each block.
Then you can either select an average trace or do what I did and also get a fast one
as well as a slow one.

The only issue is that today N needs to be much larger. I'm wondering whether we
could only run larger traces on demand? Eg. add make bench-trace that uses wget to
download compressed traces.

Cheers,
Wilco