Teo Camarasu authored 2 years ago and Ben Gamari committed 10 months ago

Supplement the existing power 2 sized nonmoving allocators with a family
of dense allocators up to a configurable threshold.

This should reduce waste from rounding up block sizes while keeping the
amount of allocator sizes manageable.

This patch:
  - Adds a new configuration option `--nonmoving-dense-allocator-count`
    to control the amount of these new dense allocators.
  - Adds some constants to `NonmovingAllocator` in order to keep
    marking fast with the new allocators.

Resolves #23340

(cherry picked from commit f830d5a34c4c972cced73b6dc25954cedf336747)
(cherry picked from commit 47e02c2ae0ea4713a2f22edf21b9a4eb5fe635be)