This adds the wasm instance to the module scope. The instance
contains the exported entities that can now be inspected.

Bug: chromium:1043034
Change-Id: I9236ac9c126f3bc4b1e056990fe34956bbe8ed6b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2213433
Commit-Queue: Kim-Anh Tran <kimanh@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67961}