test: verify multiple init via well-known symbol

Re-`require()` the addon after clearing its cache to ensure that it is
re-initialized via the well-known symbol.

PR-URL: #19875
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: Gabriel Schulhof

test/addons/hello-world/test.js

@@ -1,6 +1,13 @@
 'use strict';
 const common = require('../../common');
 const assert = require('assert');
-const binding = require(`./build/${common.buildType}/binding`);
+const bindingPath = require.resolve(`./build/${common.buildType}/binding`);
+const binding = require(bindingPath);
 assert.strictEqual(binding.hello(), 'world');
 console.log('binding.hello() =', binding.hello());
+
+// Test multiple loading of the same module.
+delete require.cache[bindingPath];
+const rebinding = require(bindingPath);
+assert.strictEqual(rebinding.hello(), 'world');
+assert.notStrictEqual(binding.hello, rebinding.hello);