This logic may be executed many times, e.g. if a hot code path uses
`{Mono,Flux}#log` or Micrometer instrumentation. The added benchmark
shows that for large stack traces the new implementation is several
orders of magnitude more efficient in terms of compute and memory
resource utilization.

While there, improve two existing benchmarks by utilizing the black hole
to which benchmark method return values are implicitly sent.

(cherry picked from commit 009ec89)