Replacing a regex in stringToPath with a quick character code check. (#3308)

lodash.js

@@ -143,7 +143,6 @@
   /** Used to match property names within property paths. */
   var reIsDeepProp = /\.|\[(?:[^[\]]*|(["'])(?:(?!\1)[^\\]|\\.)*?\1)\]/,
       reIsPlainProp = /^\w*$/,
-      reLeadingDot = /^\./,
       rePropName = /[^.[\]]+|\[(?:(-?\d+(?:\.\d+)?)|(["'])((?:(?!\2)[^\\]|\\.)*?)\2)\]|(?=(?:\.|\[\])(?:\.|\[\]|$))/g;
 
   /**
@@ -6727,7 +6726,7 @@
      */
     var stringToPath = memoizeCapped(function(string) {
       var result = [];
-      if (reLeadingDot.test(string)) {
+      if (string.charCodeAt(0) === 46 /* . */) {
         result.push('');
       }
       string.replace(rePropName, function(match, number, quote, subString) {