VM: Speed up PC descriptor verification code used in DEBUG mode.
VM: Speed up PC descriptor verification code used in DEBUG mode.

Use O(n) verification code instead of O(n*n).

BUG=https://github.com/dart-lang/sdk/issues/24596
R=srdjan@google.com

Review URL: https://codereview.chromium.org/1402123004 .

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