Node.js: renamed "require_shim" to "loader".

test/node/loader/es_modules_http/app.mjs

@@ -0,0 +1,6 @@
+import http from "http"
+
+http.createServer(function (req, res) {
+    res.writeHead(200, {'Content-Length': 12, 'Content-Type': 'text/plain'})
+       .end('Hello World\n');
+}).listen(7080);