util: use regexp instead of str.replace().join()

PR-URL: https://github.com/nodejs/node/pull/3689
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/util.js

@@ -575,13 +575,9 @@ function formatProperty(ctx, value, recurseTimes, visibleKeys, key, array) {
       }
       if (str.indexOf('\n') > -1) {
         if (array) {
-          str = str.split('\n').map(function(line) {
-            return '  ' + line;
-          }).join('\n').substr(2);
+          str = str.replace(/\n/g, '\n  ');
         } else {
-          str = '\n' + str.split('\n').map(function(line) {
-            return '   ' + line;
-          }).join('\n');
+          str = str.replace(/(^|\n)/g, '\n   ');
         }
       }
     } else {