Support multiple arguments to err/out under node + pthreads (emscripten-core#19228)

Author: sbc100

src/shell.js

@@ -446,8 +446,8 @@ if (ENVIRONMENT_IS_NODE) {
 var defaultPrint = console.log.bind(console);
 var defaultPrintErr = console.warn.bind(console);
 if (ENVIRONMENT_IS_NODE) {
-  defaultPrint = (str) => fs.writeSync(1, str + '\n');
-  defaultPrintErr = (str) => fs.writeSync(2, str + '\n');
+  defaultPrint = (...args) => fs.writeSync(1, args.join(' ') + '\n');
+  defaultPrintErr = (...args) => fs.writeSync(2, args.join(' ') + '\n');
 }
 {{{ makeModuleReceiveWithVar('out', 'print',    'defaultPrint',    true) }}}
 {{{ makeModuleReceiveWithVar('err', 'printErr', 'defaultPrintErr', true) }}}

test/test_other.py

@@ -13372,3 +13372,8 @@ def run(args, expect_bulk_mem):
   def test_memory_init_file_unsupported(self):
     err = self.expect_fail([EMCC, test_file('hello_world.c'), '-Werror', '--memory-init-file=1'])
     self.assertContained('error: --memory-init-file is only supported with -sWASM=0 [-Wunsupported] [-Werror]', err)
+
+  @node_pthreads
+  def test_node_pthreads_err_out(self):
+    create_file('post.js', 'err(1, 2, "hello"); out("foo", 42);')
+    self.do_runf(test_file('hello_world.c'), '1 2 hello\nfoo 42\n', emcc_args=['--post-js=post.js'])