Fix break on unhandled exception
Fix break on unhandled exception

A recent change broke the exception handler lookup code in the debugger.
This fixes issue 19988.

R=srdjan@google.com

Review URL: https://codereview.chromium.org//396033003

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@38267 260f80e4-7a28-3924-810f-c04153c831b5

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