[vm] Use Util::Abs instead of std::abs.
[vm] Use Util::Abs instead of std::abs.

Change-Id: I2872038ac21e5fb3a0dbe539ebe45b11ad233486
Reviewed-on: https://dart-review.googlesource.com/c/88944
Reviewed-by: Samir Jindel <5720a19f3a84f5405fa0776737a4149175e41e6a@google.com>
Commit-Queue: Samir Jindel <5720a19f3a84f5405fa0776737a4149175e41e6a@google.com>
Auto-Submit: Samir Jindel <5720a19f3a84f5405fa0776737a4149175e41e6a@google.com>

dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk