This reverts commit e80ca24c.

Reason for revert: Causes failures in the fast/regex/non-pattern-characters.html Blink web test (https://ci.chromium.org/p/v8/builders/ci/V8%20Blink%20Linux/3679)

Original change's description:
> [regexp] Rewrite error handling
> 
> This patch modifies irregexp's error handling. Instead of representing
> errors as C strings, they are represented as an enumeration value
> (RegExpError), and only converted to strings when throwing the error
> object in regexp.cc. This makes it significantly easier to integrate
> into SpiderMonkey. A few notes:
> 
> 1. Depending on whether the stack overflows during parsing or
>    analysis, the stack overflow message can vary ("Stack overflow" or
>    "Maximum call stack size exceeded"). I kept that behaviour in this
>    patch, under the assumption that stack overflow messages are
>    (sadly) the sorts of things that real world code ends up depending
>    on.
> 
> 2. Depending on the point in code where the error was identified,
>    invalid unicode escapes could be reported as "Invalid Unicode
>    escape", "Invalid unicode escape", or "Invalid Unicode escape
>    sequence". I fervently hope that nobody depends on the specific
>    wording of a syntax error, so I standardized on the first one. (It
>    was both the most common, and the most consistent with other
>    "Invalid X escape" messages.)
> 
> 3. In addition to changing the representation, this patch also adds an
>    error_pos field to RegExpParser and RegExpCompileData, which stores
>    the position at which an error occurred. This is used by
>    SpiderMonkey to provide more helpful messages about where a syntax
>    error occurred in large regular expressions.
> 
> 4. This model is closer to V8's existing MessageTemplate
>    infrastructure. I considered trying to integrate it more closely
>    with MessageTemplate, but since one of our stated goals for this
>    project was to make it easier to use irregexp outside of V8, I
>    decided to hold off.
> 
> R=​jgruber@chromium.org
> 
> Bug: v8:10303
> Change-Id: I62605fd2def2fc539f38a7e0eefa04d36e14bbde
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2091863
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66784}

TBR=jgruber@chromium.org,iireland@mozilla.com

Change-Id: I9247635f3c5b17c943b9c4abaf82ebe7b2de165e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10303
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2108550Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66786}