Merge branch 'New benchmark for hashmap lookups'

Anton Protopopov says:

====================

Add a new benchmark for hashmap lookups and fix several typos.

In commit 3 I've patched the bench utility so that now command line options
can be reused by different benchmarks.

The benchmark itself is added in the last commit 7. I was using this benchmark
to test map lookup productivity when using a different hash function [1]. When
run with --quiet, the results can be easily plotted [2].  The results provided
by the benchmark look reasonable and match the results of my different
benchmarks (requiring to patch kernel to get actual statistics on map lookups).

Links:
  [1] https://fosdem.org/2023/schedule/event/bpf_hashing/
  [2] https://github.com/aspsk/bpf-bench/tree/master/hashmap-bench

Changes,
v1->v2:
- percpu_times_index[] is of wrong size (Martin)
- use base 0 for strtol (Andrii)
- just use -q without argument (Andrii)
- use less hacks when parsing arguments (Andrii)
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>