This reverts commit 5ebb640a67.
Reason for revert: <INSERT REASONING HERE>
Original change's description:
> [vm] Finish adding support for ECMAScript 2018 features.
>
> This work pulls in v8 support for these features with
> appropriate changes for Dart and closes
> https://github.com/dart-lang/sdk/issues/34935.
>
> This adds support for the following features:
>
> * Interpreting patterns as Unicode patterns instead of
> BMP patterns
> * the dotAll flag (`/s`) for changing the behavior
> of '.' to also match line terminators
> * Escapes for character classes described by Unicode
> property groups (e.g., \p{Greek} to match all Greek
> characters, or \P{Greek} for all non-Greek characters).
>
> The following TC39 proposals describe some of the added features:
>
> * https://github.com/tc39/proposal-regexp-dotall-flag
> * https://github.com/tc39/proposal-regexp-unicode-property-escapes
>
> These additional changes are included:
>
> * Extends named capture group names to include the full
> range of identifier characters supported by ECMAScript,
> not just ASCII.
> * Changing the RegExp interface to return RegExpMatch
> objects, not Match objects, so that downcasting is
> not necessary to use named capture groups from Dart
>
> **Note**: The changes to the RegExp interface are a
> breaking change for implementers of the RegExp interface.
> Current users of the RegExp interface (i.e., code using Dart
> RegExp objects) will not be affected.
>
> Change-Id: I0709ed0a8d5db36680e32bbad585594857b9ace4
> Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/95651
> Commit-Queue: Stevie Strickland <sstrickl@google.com>
> Reviewed-by: Johnni Winther <johnniwinther@google.com>
> Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
> Reviewed-by: Martin Kustermann <kustermann@google.com>
TBR=lrn@google.com,kustermann@google.com,jmesserly@google.com,johnniwinther@google.com,sstrickl@google.com
# Not skipping CQ checks because original CL landed > 1 day ago.
Change-Id: I1eda0fee4fd9e94df095944049833a67b07277e2
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/100560
Reviewed-by: Keerti Parthasarathy <keertip@google.com>
Reviewed-by: Martin Kustermann <kustermann@google.com>
Commit-Queue: Keerti Parthasarathy <keertip@google.com>