attempt to pass on osx

ext/mini_racer_extension/extconf.rb

@@ -10,6 +10,8 @@ $CPPFLAGS += " -fPIC" unless $CPPFLAGS.split.include? "-rdynamic" or RUBY_PLATFO
 $CPPFLAGS += " -std=c++0x"
 $CPPFLAGS += " -fpermissive"
 
+$LDFLAGS.insert 0, " -stdlib=libstdc++ " if RUBY_PLATFORM =~ /darwin/
+
 if ENV['CXX']
   puts "SETTING CXX"
   CONFIG['CXX'] = ENV['CXX']