Merge pull request #1242 from laverdet/master

packages/core-js/internals/symbol-constructor-detection.js

@@ -1,13 +1,18 @@
 /* eslint-disable es/no-symbol -- required for testing */
 var V8_VERSION = require('../internals/engine-v8-version');
 var fails = require('../internals/fails');
+var global = require('../internals/global');
+
+var $String = global.String;
 
 // eslint-disable-next-line es/no-object-getownpropertysymbols -- required for testing
 module.exports = !!Object.getOwnPropertySymbols && !fails(function () {
   var symbol = Symbol();
   // Chrome 38 Symbol has incorrect toString conversion
   // `get-own-property-symbols` polyfill symbols converted to object are not Symbol instances
-  return !String(symbol) || !(Object(symbol) instanceof Symbol) ||
+  // nb: Do not call `String` directly to avoid this being optimized out to `symbol+''` which will,
+  // of course, fail.
+  return !$String(symbol) || !(Object(symbol) instanceof Symbol) ||
     // Chrome 38-40 symbols are not inherited from DOM collections prototypes to instances
     !Symbol.sham && V8_VERSION && V8_VERSION < 41;
 });