This default constructor is used in a couple of places (e.g. compilation-cache.cc) to hold a default value that is later overwritten.
See
https://chromium.googlesource.com/chromium/src/+/HEAD/styleguide/c++/c++-dos-and-donts.md#prefer-to-use.

Bug: v8:10488
Change-Id: Ibe4741cebdcf7c350580de3e6b0bd10fd8b7be73
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2240504Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68327}