Currently all instances share the exact same export wrappers (pointed
to by the corresponding compiled module). This bug, however, does not
cause a problem at runtime. This CL makes sure that all compiled modules
have their own export wrapper table during instance instantiation.

Change-Id: I385d79ab8ad42672f7ab72755387d161b1e9ee81
Reviewed-on: https://chromium-review.googlesource.com/937715
Commit-Queue: Kim-Anh Tran <kimanh@google.com>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51585}