Make use of new "isPotentiallyMutated..." API in ResolverVisitor.
Make use of new "isPotentiallyMutated..." API in ResolverVisitor.

With this change there are no remaining uses of the old
"isPotentiallyMutated..." API anywhere in analyzer (outside of tests).

R=brianwilkerson@google.com

Review URL: https://codereview.chromium.org/1705173002 .

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