testsuite: add test for wasm promise.throwTo() logic

This commit adds a test case to test the wasm backend
promise.throwTo() logic.

testsuite/tests/jsffi/all.T

@@ -11,6 +11,8 @@ setTestOpts([
   extra_ways(['compacting_gc', 'nonmoving', 'sanity'])
 ])
 
+test('cancel', [], compile_and_run, ['-optl-Wl,--export=setTimeout'])
+
 test('gameover', [], compile_and_run, ['-optl-Wl,--export=testJSException,--export=testHSException'])
 
 test('http', [], compile_and_run, ['-optl-Wl,--export=main'])

testsuite/tests/jsffi/cancel.hs

+module Test where
+
+import Control.Exception
+
+foreign import javascript safe "new Promise(res => setTimeout(res, $1))"
+  js_setTimeout :: Int -> IO ()
+
+setTimeout :: Int -> IO ()
+setTimeout t = evaluate =<< js_setTimeout t
+
+foreign export javascript "setTimeout"
+  setTimeout :: Int -> IO ()

testsuite/tests/jsffi/cancel.mjs

+export default async (__exports) => {
+  const test = new Promise((res) => {
+    const p = __exports.setTimeout(114514);
+    p.throwTo("1919810");
+    p.catch((err) => {
+      console.log(`${err}`.split("\n")[0]);
+      res();
+    });
+  });
+
+  await test;
+  process.exit();
+};

testsuite/tests/jsffi/cancel.stdout

+RuntimeError: JSException "1919810"