For use in tsweb debug handlers, so that we can easily inspect cache
and limiter state when troubleshooting.
Updates tailscale/corp#3601
Signed-off-by: David Anderson <danderson@tailscale.com>
The benchmark simulates an LRU being queries with uniformly random
inputs, in a set that's too large for the LRU, which should stress
the eviction codepath.
Signed-off-by: David Anderson <danderson@tailscale.com>