Modify Bigint _mulAdd, _sqrAdd, _estQuotientDigit, and Montgomery _mulMod
methods to return the number of digits processed, so that their intrinsified
versions on 64-bit platforms can process digit pairs.

R=zra@google.com

Review URL: https://codereview.chromium.org//811763004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42568 260f80e4-7a28-3924-810f-c04153c831b5
This fixes the native ARM bot and other builds depending on standalone.deps.

- Fix standalone.deps by adding args and logging packages.

Review URL: https://codereview.chromium.org//810103005

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@42569 260f80e4-7a28-3924-810f-c04153c831b5