These tests cover the basic VirtualAddressSpace functionality for the
three different types of address spaces currently available: the root
space, subspaces, and emulated subspaces.

This CL also includes minor bugfixes in VirtualAddressSpace
implementations and removes RandomizedVirtualAlloc in platform-win32.cc
which doesn't seem to do anything useful anymore but prevents page
allocation hints from working correctly.

Bug: v8:10391
Change-Id: Ifa260d18fd366516b5a41ab42ce2f1785c57d061
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3386801Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78666}