Remove code that analyzes tos values from tickprocessor

Assuming that the value on top of stack is return address for a frameless invocation is error-prone. Corresponding logic was removed from profile-generator.cc in r14205 (see https://code.google.com/p/v8/source/diff?spec=svn14205&r=14205&format=side&path=/branches/bleeding_edge/src/profile-generator.cc) and now it is time to remove it from the tick processor.

Since the tos is not used anymore by profiler it is also removed from TickSample.

BUG=None

Review URL: https://codereview.chromium.org/13873009

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@14252 ce2b1a6d-e550-0410-aec6-3dcde31c8c00