COMP: Add preprocessor symbols to double-conversion for OS X PPC

The powerpc preprocessor definitions did not include the ones
actually found on Mac OS X on PPC. Added these flags to utils.h

Change-Id: Ifd5e83295c7e5372616c1fc5a51280658f9d6abe
Merge topic 'DoubleConversionPPCFix'

5e6b8cd COMP: Add preprocessor symbols to double-conversion for OS X PPC