This reverts commit d16bce9d.

Reason for revert: Investigating what caused the redness here:
https://ci.chromium.org/p/v8/builders/luci.v8.ci/V8-Blink%20Mac/15097

Original change's description:
> [parser] Removed unnecessary copies
> 
> Bug: v8:8015
> Change-Id: I2ee074559484b9865dc1a27e6ea697ca311ee7ee
> Reviewed-on: https://chromium-review.googlesource.com/1185198
> Reviewed-by: Marja Hölttä <marja@chromium.org>
> Commit-Queue: Florian Sattler <sattlerf@google.com>
> Cr-Commit-Position: refs/heads/master@{#55327}

TBR=marja@chromium.org,sattlerf@google.com

Change-Id: I0344b11c2538a2755315dae7dd1f1ab62b8e069c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:8015
Reviewed-on: https://chromium-review.googlesource.com/1186441Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55343}