Revert of [fullcodegen] Remove the hacky %_FastOneByteArrayJoin intrinsic. (patchset #1 id:1 of https://codereview.chromium.org/1708523002/ )

Reason for revert:
[Sheriff] Speculative revert for adding arm flakes:
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm%20-%20sim/builds/5756
https://build.chromium.org/p/client.v8/builders/V8%20Linux%20-%20arm%20-%20sim%20-%20novfp3/builds/3375/

And some more...

Original issue's description:
> [fullcodegen] Remove the hacky %_FastOneByteArrayJoin intrinsic.
>
> This intrinsic was only supported in fullcodegen, and is actually no
> longer relevant for SunSpider peak performance it seems, so let's get
> rid of it and maybe just implement Array.prototype.join with a fast
> path at some point instead.
>
> R=mstarzinger@chromium.org
>
> Committed: https://crrev.com/ccf12b4bede3f1ce3ce14fb33bcc4041525a40af
> Cr-Commit-Position: refs/heads/master@{#34084}

TBR=mstarzinger@chromium.org,bmeurer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/1709693002

Cr-Commit-Position: refs/heads/master@{#34091}