This is a reland of af677f29, fixing
an issue with negative indices.

Original change's description:
> [ic] EmitElementStore: don't miss when hitting new space limit.
>
> CSA::EmitElementStore used to bail out (IC miss) via
> CSA::CheckForCapacityGrow when the capacity hits the new space
> limit, causing the store IC to go megamorphic in my example (see
> referenced bug). With this CL, we do what TF'ed code does already:
> call into Runtime::kGrowArrayElements (in this situation), thus
> staying monomorphic.
>
> Here's a contrived test case:
>
> ////////////////////////
> let x = [];
>
> function bar() {
>   for (let i = 0; i < 50000; ++i) x[i] = i;
> }
>
> function foo() {
>   for (let i = x.length; i < 100e6; ++i) x[i] = i;
> }
>
> bar();
> foo();
> ////////////////////////
>
> This took about 4s on my machine, now it takes 3s.
>
> Bug: v8:7447
> Change-Id: I7f268fc55835f363d250613ce0357444a663051c
> Reviewed-on: https://chromium-review.googlesource.com/918723
> Commit-Queue: Georg Neis <neis@chromium.org>
> Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#51297}

Bug: v8:7447, chromium:812451
Change-Id: I345b5e5b2437c4f50e42bbd87947630f24cd95eb
Reviewed-on: https://chromium-review.googlesource.com/921201
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51311}