Added the simplest call stack sampling and call profile in tick processor output.

Added the simplest call stack sampling and call profile in tick processor output.

Currently only two stack frames are sampled (current function and its caller).

Output of tick processor looks like this:

 [Call profile]:
   total  call path
   15.2%  LazyCompile: am3 crypto.js:108  <-  LazyCompile: montReduce crypto.js:583
    6.5%  LazyCompile: am3 crypto.js:108  <-  LazyCompile: bnpSquareTo crypto.js:431
    2.9%  Builtin: KeyedStoreIC_Generic  <-  LazyCompile: montReduce crypto.js:583
    2.3%  LazyCompile: am3 crypto.js:108  <-  LazyCompile: bnpMultiplyTo crypto.js:415

Tested under Windows, Linux and OS X.

Review URL: http://codereview.chromium.org/21403

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@1292 ce2b1a6d-e550-0410-aec6-3dcde31c8c00