cmd/bent: candidate new benchmarks-100.toml

This set was chosen
- to reduce both run-to-run and
  branch-alignment benchmark noise,
- to call a larger number of
  functions for at least 2% of
  at least one benchmark,
- to call more generic functions.

This is a bit of an experiment; the hope is
that changes will be detected when they occur,
and that spurious wild-goose-chases in triage
will occur less often.

Change-Id: If571b9b589312a79c9b0aad28ba1c7344faa8d8f
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/813860
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>