Make the free and allocated lists simply linked lists of `Metadata*`
(instead of `Metadata*` pointing to Trampoline, which - via some
logic - can be translated into next `Metadata*`).
Make the layout of the virtual address space mapping and
offsets `constexpr` functions instead of computing them at
runtime & caching in fields.
Use `uword` to represent `Trampoline` entrypoint (as we generally
use `uword` for `Code.EntryPoint()` / ...)
TEST=ci
Change-Id: If4ffa11712acc46c9295b609caff7576d2354fe4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/305983
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Daco Harkes <dacoharkes@google.com>
Martin Kustermann
219bf34064