test: add basic WebAssembly test

Tests a basic WebAssembly module that adds two numbers.
wasm example from the WebAssembly/wabt repo licensed
Apache 2.0.

Refs: https://github.com/WebAssembly/wabt/blob/49b7984544ddaf14d5e2f1ad9115dad7e9a2b299/demo/wat2wasm/examples.js#L27-L32
PR-URL: #16760
Reviewed-By: Anna Henningsen <[email protected]>
Reviewed-By: Colin Ihrig <[email protected]>
Reviewed-By: Myles Borins <[email protected]>
Reviewed-By: Sakthipriyan Vairamani <[email protected]>
Reviewed-By: Yuta Hiroto <[email protected]>

Author: stevekinney

test/.eslintrc.yaml

@@ -15,3 +15,7 @@ rules:
   inspector-check: error
   ## common module is mandatory in tests
   required-modules: [error, common]
+
+# Global scoped methods and vars
+globals:
+  WebAssembly: false

test/fixtures/test.wasm

@@ -0,0 +1,18 @@
+'use strict';
+
+require('../common');
+
+const assert = require('assert');
+const fixtures = require('../common/fixtures');
+
+const buffer = fixtures.readSync('test.wasm');
+
+assert.ok(WebAssembly.validate(buffer), 'Buffer should be valid WebAssembly');
+
+WebAssembly.instantiate(buffer, {}).then((results) => {
+  assert.strictEqual(
+    results.instance.exports.addTwo(10, 20),
+    30,
+    'Exported function should add two numbers.',
+  );
+});