Use only one defineProperty reference.

lodash.js

@@ -1469,7 +1469,6 @@
         Symbol = context.Symbol,
         Uint8Array = context.Uint8Array,
         allocUnsafe = Buffer ? Buffer.allocUnsafe : undefined,
-        defineProperty = Object.defineProperty,
         getPrototype = overArg(Object.getPrototypeOf, Object),
         iteratorSymbol = Symbol ? Symbol.iterator : undefined,
         objectCreate = Object.create,
@@ -1477,6 +1476,14 @@
         splice = arrayProto.splice,
         spreadableSymbol = Symbol ? Symbol.isConcatSpreadable : undefined;
 
+    var defineProperty = (function() {
+      try {
+        var func = getNative(Object, 'defineProperty');
+        func({}, '', {});
+        return func;
+      } catch (e) {}
+    }());
+
     /** Mocked built-ins. */
     var ctxClearTimeout = context.clearTimeout !== root.clearTimeout && context.clearTimeout,
         ctxNow = Date && Date.now !== root.Date.now && Date.now,
@@ -1503,8 +1510,7 @@
         Promise = getNative(context, 'Promise'),
         Set = getNative(context, 'Set'),
         WeakMap = getNative(context, 'WeakMap'),
-        nativeCreate = getNative(Object, 'create'),
-        nativeDefineProperty = getNative(Object, 'defineProperty');
+        nativeCreate = getNative(Object, 'create');
 
     /** Used to store function metadata. */
     var metaMap = WeakMap && new WeakMap;
@@ -3987,8 +3993,8 @@
      * @param {Function} string The `toString` result.
      * @returns {Function} Returns `func`.
      */
-    var baseSetToString = !nativeDefineProperty ? identity : function(func, string) {
-      return nativeDefineProperty(func, 'toString', {
+    var baseSetToString = !defineProperty ? identity : function(func, string) {
+      return defineProperty(func, 'toString', {
         'configurable': true,
         'enumerable': false,
         'value': constant(string),