If enabled, this mode moves code for isolate-independent builtins off
the JS heap at Isolate creation. The Code object itself is rewritten
to tail-call the off-heap instruction stream.

Drive-by-fix: Support lazy deserialization in asm-wasm instantiation.

Bug: v8:6666
Change-Id: Ic109527ff478cfc6e8942e924413fc7532da6eaf
Reviewed-on: https://chromium-review.googlesource.com/888562Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51015}