wasm: fix dyld setImmediate usage in browser

The wasm dyld script used to only run in node and directly uses
setImmediate in globalThis. In case of browsers, it needs to import
setImmediate from the prelude, hence this commit.

utils/jsffi/dyld.mjs

@@ -93,7 +93,7 @@ import fs from "node:fs";
 import path from "node:path";
 import stream from "node:stream";
 import { WASI } from "node:wasi";
-import { JSValManager } from "./prelude.mjs";
+import { JSValManager, setImmediate } from "./prelude.mjs";
 import { parseRecord, parseSections } from "./post-link.mjs";
 
 // Make a consumer callback from a buffer. See Parser class

utils/jsffi/prelude.mjs

@@ -39,7 +39,7 @@ export class JSValManager {
 // To benchmark different setImmediate() implementations in the
 // browser, use https://github.com/jphpsf/setImmediate-shim-demo as a
 // starting point.
-const setImmediate = await (async () => {
+export const setImmediate = await (async () => {
   // node, bun, or other scripts might have set this up in the browser
   if (globalThis.setImmediate) {
     return globalThis.setImmediate;