Fix test compilation for FreeBSD (#433)

test/posix-mock-test.cc

@@ -502,7 +502,7 @@ LocaleType newlocale(int category_mask, const char *locale, LocaleType base) {
   return LocaleMock::instance->newlocale(category_mask, locale, base);
 }
 
-#ifdef __APPLE__
+#if defined(__APPLE__) || defined(__FreeBSD__)
 typedef int FreeLocaleResult;
 #else
 typedef void FreeLocaleResult;