Multiple code spaces are cheaper on 32-bit systems, because we can
directly call between them. Over-reservation on the other hand increases
the chance for OOMs. Hence reduce the code space estimation (used for
the initial reservation) on 32-bit systems.

Numbers were obtained from an older Epic module, Photoshop, and AutoCAD.
I'll keep an eye on the {V8.WasmModuleNumberOfCodeSpaces} counter.

R=ahaas@chromium.org

Change-Id: Ide804eaf46e8ba9bb48fcb41f23f1facc910645e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3634778
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80425}