Reason for revert:
Speculative revert for christmas tree
Original issue's description:
> Reland: [modules] Properly initialize declared variables.
>
> Before evaluating a module, all variables declared at the top-level
> in _any_ of the modules in the dependency graph must be initialized.
> This is observable because a module A can access a variable imported
> from module B (e.g. a function) at a point when module B's body hasn't
> been evaluated yet.
>
> We achieve this by implementing modules internally as generators with
> two states (not initialized, initialized).
>
> R=adamk@chromium.org
> BUG=v8:1569
> CQ_INCLUDE_TRYBOTS=master.tryserver.v8:v8_win_dbg
>
> Committed: https://crrev.com/f4dfb6fbe1cdd9a0f287a1a9c496e1f69f6f5d20
> Committed: https://crrev.com/8c52a411583e870bd5ed100864caa58f491c5d88
> Cr-Original-Commit-Position: refs/heads/master@{#39871}
> Cr-Commit-Position: refs/heads/master@{#39892}
TBR=adamk@chromium.org,mstarzinger@chromium.org,machenbach@chromium.org,neis@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:1569
Review-Url: https://codereview.chromium.org/2387593002
Cr-Commit-Position: refs/heads/master@{#39896}
669cb71e60