Many methods currently defined in WasmCompiledModule actually only use
shared information from WasmSharedModuleData. Hence, move them to this
class.

R=ahaas@chromium.org

Bug: chromium:750256
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: Ia298306c3757fca8e2d93eaaf3424d6f91150212
Reviewed-on: https://chromium-review.googlesource.com/831509Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50156}