test: replace commented out expectations with tests

Signed-off-by: Darshan Sen <raisinten@gmail.com>

PR-URL: nodejs#41667
Reviewed-By: Mestery <mestery@protonmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/js-native-api/test_symbol/test2.js

@@ -6,10 +6,12 @@ const assert = require('assert');
 const test_symbol = require(`./build/${common.buildType}/test_symbol`);
 
 const fooSym = test_symbol.New('foo');
+assert.strictEqual(fooSym.toString(), 'Symbol(foo)');
+
 const myObj = {};
 myObj.foo = 'bar';
 myObj[fooSym] = 'baz';
-Object.keys(myObj); // -> [ 'foo' ]
-Object.getOwnPropertyNames(myObj); // -> [ 'foo' ]
-Object.getOwnPropertySymbols(myObj); // -> [ Symbol(foo) ]
-assert.strictEqual(Object.getOwnPropertySymbols(myObj)[0], fooSym);
+
+assert.deepStrictEqual(Object.keys(myObj), ['foo']);
+assert.deepStrictEqual(Object.getOwnPropertyNames(myObj), ['foo']);
+assert.deepStrictEqual(Object.getOwnPropertySymbols(myObj), [fooSym]);