This is a reland of 0e22ec73

Original change's description:
> [regexp] Escape newlines when setting [[OriginalSource]]
> 
> This escapes LineTerminator characters in a regexp pattern when
> creating the string that will be stored in the [[OriginalSource]] slot.
> 
> As an example, the source property for all following objects will equal
> "\n" (a '\' character followed by 'n'):
> 
>   /\n/
>   new RegExp("\n")
>   new RegExp("\\n")
> 
> Bug: v8:1982, chromium:855009
> Change-Id: I3b539497a0697e3d51ec969cae49308b0b312a19
> Reviewed-on: https://chromium-review.googlesource.com/c/1384316
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Mathias Bynens <mathias@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58387}

Bug: v8:1982, chromium:855009
Change-Id: I1ba22395477ec37e8e8c944000f9beade1e3250b
Reviewed-on: https://chromium-review.googlesource.com/c/1386495Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58419}