zip: add isUnixSymlink.

Author: ctalkington

lib/archivers/zip/zip-archive-entry.js

@@ -218,6 +218,10 @@ ZipArchiveEntry.prototype.isDirectory = function() {
   return this.getName().slice(-1) === '/';
 };
 
+ZipArchiveEntry.prototype.isUnixSymlink = function() {
+  return (this.getUnixMode() & constants.S_IFLINK) === constants.S_IFLINK;
+};
+
 ZipArchiveEntry.prototype.isZip64 = function() {
   return this.csize > constants.ZIP64_MAGIC || this.size > constants.ZIP64_MAGIC;
 };