TickProcessor: more accurate mapping of statically compiled code on Linux.

TickProcessor: more accurate mapping of statically compiled code on Linux.

'nm' is now called with an option to report function code sizes. Static code entries are restricted to the sizes reported, and the remaining unnamed code is attributed to a library as a whole. This makes reports more accurate, as some functions are tiny, but has chunks of unnamed code behind them.

This change doesn't affect reporting on Windows, as in .map files function code sizes aren't specified.

Review URL: http://codereview.chromium.org/149513

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2455 ce2b1a6d-e550-0410-aec6-3dcde31c8c00