AMD Bulldozer "bdver1" Compiler Performance

For all four tested compilers, manually setting the march/mtune flags to "bdver1" for the single-threaded POV-Ray benchmark led to a noticeable performance improvement. The binaries from Open64 and GCC were both significantly faster. Between GCC and Open64, the lead was slightly in favor of GCC, but there was not a huge difference. For GCC when adding in the "-Ofast" optimization level, the binaries were not much faster than using the Bulldozer optimizations alone.