Support instruction-level perf event profiling to Dart VM using V8's ll_prof.py.
Support instruction-level perf event profiling to Dart VM using V8's ll_prof.py.

Usage:

1) perf record -g out/ReleaseIA32/dart --ll-prof example.dart
2) third_party/v8/tools/ll_prof.py --disasm-top=3

This will produce a  per-function and a per-instruction profile with 
disassembly for the top 3 function in the profile.

Currently only available on Linux.
Review URL: https://codereview.chromium.org//12342012

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@19044 260f80e4-7a28-3924-810f-c04153c831b5

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