Bump to v4.12.0.

_Stack.js

@@ -1,3 +1,4 @@
+import ListCache from './_ListCache';
 import stackClear from './_stackClear';
 import stackDelete from './_stackDelete';
 import stackGet from './_stackGet';
@@ -9,17 +10,10 @@ import stackSet from './_stackSet';
  *
  * @private
  * @constructor
- * @param {Array} [values] The values to cache.
+ * @param {Array} [entries] The key-value pairs to cache.
  */
-function Stack(values) {
-  var index = -1,
-      length = values ? values.length : 0;
-
-  this.clear();
-  while (++index < length) {
-    var entry = values[index];
-    this.set(entry[0], entry[1]);
-  }
+function Stack(entries) {
+  this.__data__ = new ListCache(entries);
 }
 
 // Add methods to `Stack`.