...from the Store constructor/destructor. They were preventing embedders
from using several Stores with overlapping but non-nested lifetimes.
Without Isolate::Enter, such use cases are supported; the only consequence
is that Isolate::Current will not work and therefore must not be called;
but it is deprecated and not called from the Wasm C API anyway.

Change-Id: I65eda00243126e189febb0fd8b38a953c4ee078f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1698387
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62692}