This reverts commit 5c1babcc.

This seems to regress a range of benchmarks on ia32:
  Emscripten for Fannkuch, Zlib, MemOps, Life, Bullet
  AreWeFastYet for BulletLoadTime, Fasta, Fannkuch
  JetStream for towers.c, quicksort.c, gcc-loops.cpp, bigfib.cpp

BUG=673861
R=jarin@chromium.org,shiyu.zhang@intel.com

Review-Url: https://codereview.chromium.org/2573983003
Cr-Commit-Position: refs/heads/master@{#41696}