This will lazily compile all wasm modules. Just for experimenting
currently.

R=ahaas@chromium.org
BUG=v8:5991

Change-Id: I51fc3655e15f55e87d9fec86ff5dca109fb052be
Reviewed-on: https://chromium-review.googlesource.com/458008Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44044}