Even though descriptor arrays are references by maps in the old
generation, they seems to be short living in benchmarks.

This fixes perf regressions introduced in 1ad0cd56.

Bug:chromium:911073,chromium:910567,chromium:910443,

Change-Id: Iaf933d409e72c6c26df48f6435f9543224ea7d67
Reviewed-on: https://chromium-review.googlesource.com/c/1363146Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58050}