The interface of {WasmCompiledModule} currently mostly receives and
provides handles to the contained data. Other interfaces don't (see
{object-macros.h}.
This leads to performance and memory overhead for chained accesses like
{instance->compiled_module()->shared()->script()}, because intermediate
accessors allocate Handles for no reason. It also breaks the
constraints that lower-case accessors should be trivial to execute, but
allocating a handle is not trivial (should not be done in a loop if not
needed).
It also silences gcmole errors, as documented in
https://crrev.com/c/832268.

R=ahaas@chromium.org, mtrofin@chromium.org

Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ib82fb295977a47b4a8ab9bae9c9b6e2b235ad5e5
Reviewed-on: https://chromium-review.googlesource.com/832387
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Mircea Trofin <mtrofin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50173}