Revert "Correctly report callstack when current function is FunctionCall builtin"

This reverts commit r15426. The new test fails in Debug mode.

BUG=None
TBR=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/18478002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@15434 ce2b1a6d-e550-0410-aec6-3dcde31c8c00