HeapProfiler: provide human readable names for code objects.

HeapProfiler: provide human readable names for code objects.

It is very hard to understand the structure of the heap even for about:blank page
because code objects in the heap have no names. This patch propagates the names
for Code::STUB and Code::BUILTIN code objects.
Also it assign function names from SharedFunctionInfo to the code objects.

BUG=
R=alph@chromium.org, svenpanne@chromium.org, yurys@chromium.org

Review URL: https://codereview.chromium.org/52643002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17486 ce2b1a6d-e550-0410-aec6-3dcde31c8c00