StopCpuProfiling should return non-const CpuProfile

StopCpuProfiling is replaced with StopProfiling which returns non-const CpuProfile which allows to call CpuProfile::Delete on it without const_cast. Also replaced StartCpuProfiling with StartProfiling to have symmetric names for start/stop actions.

BUG=v8:3213
LOG=Y
R=alph@chromium.org, svenpanne@chromium.org

Review URL: https://codereview.chromium.org/197873015

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19918 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Continued fix for 351257. Reusing the feedback vector is too complex.

Attempting to re-use the type feedback vector stored in the
SharedFunctionInfo turns out to be difficult among the various cases.
It will be much easier to do this when deferred type feedback processing
is removed, as is in the works.

Created bug v8:3212 to track re-introducing the optimization of reusing
the type vector on recompile before optimization.

The CL also brings back the type vector on the SharedFunctionInfo.

BUG=351257
LOG=Y
R=bmeurer@chromium.org, bmeuer@chromium.org

Review URL: https://codereview.chromium.org/199973004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@19919 ce2b1a6d-e550-0410-aec6-3dcde31c8c00