test: add known issue for vm module

GlobalPropertySetterCallback() does not check the
property on the sandbox. It wrongly throws an error
instead of updating `x`.

PR-URL: #14661
Ref: #12300
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: Timothy Gu <timothygu99@gmail.com>

test/known_issues/test-vm-strict-mode.js

@@ -0,0 +1,17 @@
+'use strict';
+// https://github.com/nodejs/node/issues/12300
+
+require('../common');
+const assert = require('assert');
+const vm = require('vm');
+
+const ctx = vm.createContext({ x: 42 });
+
+// The following line wrongly throws an
+// error because GlobalPropertySetterCallback()
+// does not check if the property exists
+// on the sandbox. It should just set x to 1
+// instead of throwing an error.
+vm.runInContext('"use strict"; x = 1', ctx);
+
+assert.strictEqual(ctx.x, 1);