workaround compile issues on Darwin (OS X)
workaround compile issues on Darwin (OS X)

Signed-off-by: Ben Noordhuis <59bd0a3ff43b32849b319e645d4798d8a5d1e889@bnoordhuis.nl>

xenophy/node-iconv,takano32/node-iconv,xenophy/node-iconv,takano32/node-iconv