The constructor of AbstractState isn't doing anything interesting, so
can be removed.

See
https://chromium.googlesource.com/chromium/src/+/HEAD/styleguide/c++/c++-dos-and-donts.md#prefer-to-use.

Bug: v8:10488
Change-Id: If413a69aa83689f55a51e48179b75287a4620d5e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2233857Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68272}