The deoptimizer searched the stack for activations of the same function to
determine whether to trigger lazy deopting. Since we share optimized code we
actually need to search for activations of the same code (but potentially
different functions).

R=jkummerow@chromium.org
BUG=chromium:147475
TEST=mjsunit/regress/regress-crbug-147475

Review URL: https://chromiumcodereview.appspot.com/10917162

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12473 ce2b1a6d-e550-0410-aec6-3dcde31c8c00