Bump to v4.16.4.

_baseToString.js

@@ -1,4 +1,6 @@
 import Symbol from './_Symbol.js';
+import arrayMap from './_arrayMap.js';
+import isArray from './isArray.js';
 import isSymbol from './isSymbol.js';
 
 /** Used as references for various `Number` constants. */
@@ -21,6 +23,10 @@ function baseToString(value) {
   if (typeof value == 'string') {
     return value;
   }
+  if (isArray(value)) {
+    // Recursively convert values (susceptible to call stack limits).
+    return arrayMap(value, baseToString) + '';
+  }
   if (isSymbol(value)) {
     return symbolToString ? symbolToString.call(value) : '';
   }