Remove old JIT and engine bug guards.

lodash.js

@@ -2824,12 +2824,7 @@
      * @returns {boolean} Returns `true` if `key` exists, else `false`.
      */
     function baseHas(object, key) {
-      // Avoid a bug in IE 10-11 where objects with a [[Prototype]] of `null`,
-      // that are composed entirely of index properties, return `false` for
-      // `hasOwnProperty` checks of them.
-      return object != null &&
-        (hasOwnProperty.call(object, key) ||
-          (typeof object == 'object' && key in object && getPrototype(object) === null));
+      return object != null && hasOwnProperty.call(object, key);
     }
 
     /**
@@ -4004,7 +3999,7 @@
       object = parent(object, path);
 
       var key = toKey(last(path));
-      return !(object != null && baseHas(object, key)) || delete object[key];
+      return !(object != null && hasOwnProperty.call(object, key)) || delete object[key];
     }
 
     /**
@@ -5412,7 +5407,7 @@
       var index = objLength;
       while (index--) {
         var key = objProps[index];
-        if (!(isPartial ? key in other : baseHas(other, key))) {
+        if (!(isPartial ? key in other : hasOwnProperty.call(other, key))) {
           return false;
         }
       }
@@ -5548,19 +5543,6 @@
       return arguments.length ? result(arguments[0], arguments[1]) : result;
     }
 
-    /**
-     * Gets the "length" property value of `object`.
-     *
-     * **Note:** This function is used to avoid a
-     * [JIT bug](https://bugs.webkit.org/show_bug.cgi?id=142792) that affects
-     * Safari on at least iOS 8.1-8.3 ARM64.
-     *
-     * @private
-     * @param {Object} object The object to query.
-     * @returns {*} Returns the "length" value.
-     */
-    var getLength = baseProperty('length');
-
     /**
      * Gets the data for `map`.
      *
@@ -10888,7 +10870,7 @@
      * // => false
      */
     function isArrayLike(value) {
-      return value != null && isLength(getLength(value)) && !isFunction(value);
+      return value != null && isLength(value.length) && !isFunction(value);
     }
 
     /**
@@ -12838,7 +12820,7 @@
           length = result.length;
 
       for (var key in object) {
-        if (baseHas(object, key) &&
+        if (hasOwnProperty.call(object, key) &&
             !(skipIndexes && (key == 'length' || isIndex(key, length))) &&
             !(isProto && key == 'constructor')) {
           result.push(key);