We don't use these for benchmarking anymore.
Now we have the go1 dir and the benchmarks subrepo.
Some have problematic copyright notices, so move out of main repo.
Preserved in golang.org/x/exp/shootout.
Fixes#12688.
Fixes#13584.
Change-Id: Ic0b71191ca1a286d33d7813aca94bab1617a1c82
Reviewed-on: https://go-review.googlesource.com/18320
Reviewed-by: Ian Lance Taylor <iant@golang.org>