AMD Bulldozer (or Opteron_G4 as called in QEMU) was added to the list
of cpu models, flags were taken from upstream qemu cpu specifications
and should be sorted by bit values (or first occurence in the feature
specification part of cpu_map.xml).

Based on QEMU upstream commit 885bb0369a4f0abe2c0185178f3cb347cb02cdf1.