am e0881796: am 8081a8b5: am 13169ccb: Merge "Revert "Switch x86 and x86_64 build to use GCC 4.9""

* commit 'e088179677b50cac9ef7c1ab83e89ed338a9b7ed':
  Revert "Switch x86 and x86_64 build to use GCC 4.9"