[test] Enable stdout/stderr logging by default in browser tests

Author: sbc100

test/common.py

@@ -2129,6 +2129,8 @@ def do_POST(self):
         self.end_headers()
       else:
         print(f'do_POST: unexpected POST: {urlinfo}')
+        self.send_response(404)
+        self.end_headers()
 
     def do_GET(self):
       info = urlparse(self.path)

tools/link.py

@@ -797,7 +797,7 @@ def phase_linker_setup(options, linker_args):  # noqa: C901, PLR0912, PLR0915
   def limit_incoming_module_api():
     if options.oformat == OFormat.HTML and options.shell_path == DEFAULT_SHELL_HTML:
       # Out default shell.html file has minimal set of INCOMING_MODULE_JS_API elements that it expects
-      default_setting('INCOMING_MODULE_JS_API', 'canvas,monitorRunDependencies,onAbort,onExit,print,setStatus'.split(','))
+      default_setting('INCOMING_MODULE_JS_API', 'canvas,monitorRunDependencies,onAbort,onExit,print,printErr,setStatus'.split(','))
     else:
       default_setting('INCOMING_MODULE_JS_API', [])