Revert "Rewrite a test to count emitted instructions without using -stats"

This reverts commit aac7922b8fe7ae733d3fe6697e6789fd730315dc. I am reverting the
commit since it broke the phase 1 public buildbot for a few hours.

http://lab.llvm.org:8013/builders/clang-x86_64-darwin11-nobootstrap-RA/builds/2137