Error on EXPORT_NAME without MODULARIZE. NFC

One doesn't make sense without that other.

Fixes: #17274

emcc.py

diff --git a/emcc.py b/emcc.py
index f150928..96bc1a2 100755
--- a/emcc.py
+++ b/emcc.py
@@ -2567,6 +2567,9 @@
   if not js_manipulation.isidentifier(settings.EXPORT_NAME):
     exit_with_error(f'EXPORT_NAME is not a valid JS identifier: `{settings.EXPORT_NAME}`')
 
+  if not settings.MODULARIZE and 'EXPORT_NAME' in user_settings:
+    exit_with_error('-sEXPORT_NAME can only be used with -sMODULARIZE')
+
   if settings.EMSCRIPTEN_TRACING and settings.ALLOW_MEMORY_GROWTH:
     settings.DEFAULT_LIBRARY_FUNCS_TO_INCLUDE += ['emscripten_trace_report_memory_layout']
     settings.REQUIRED_EXPORTS += ['emscripten_stack_get_current',

site/source/docs/getting_started/FAQ.rst

diff --git a/site/source/docs/getting_started/FAQ.rst b/site/source/docs/getting_started/FAQ.rst
index 7214734..d9403e6 100644
--- a/site/source/docs/getting_started/FAQ.rst
+++ b/site/source/docs/getting_started/FAQ.rst
@@ -372,8 +372,8 @@
 call to create an instance of your module. The factory function returns a
 Promise that resolves with the module instance. The promise is resolved once
 it's safe to call the compiled code, i.e. after the compiled code has been
-downloaded and instantiated. For example, if you build with ``-sMODULARIZE -s
-'EXPORT_NAME="createMyModule"'``, then you can do this:
+downloaded and instantiated. For example, if you build with ``-sMODULARIZE
+-sEXPORT_NAME=createMyModule``, then you can do this:
 
 ::
 

tests/test_other.py

diff --git a/tests/test_other.py b/tests/test_other.py
index 602cfb4..b3eda31 100644
--- a/tests/test_other.py
+++ b/tests/test_other.py
@@ -5578,9 +5578,8 @@
     assert output.stdout == 'hello, world!\n' and output.stderr == '', 'expected output, got\n===\nSTDOUT\n%s\n===\nSTDERR\n%s\n===\n' % (output.stdout, output.stderr)
 
   def test_EXPORT_NAME_with_html(self):
-    result = self.run_process([EMCC, test_file('hello_world.c'), '-o', 'a.html', '-sEXPORT_NAME=Other'], stdout=PIPE, check=False, stderr=STDOUT)
-    self.assertNotEqual(result.returncode, 0)
-    self.assertContained('Customizing EXPORT_NAME requires that the HTML be customized to use that name', result.stdout)
+    err = self.expect_fail([EMCC, test_file('hello_world.c'), '-o', 'a.html', '-sEXPORT_NAME=Other', '-sMODULARIZE'])
+    self.assertContained('Customizing EXPORT_NAME requires that the HTML be customized to use that name', err)
 
   def test_modularize_sync_compilation(self):
     create_file('post.js', r'''
@@ -6805,8 +6804,8 @@
   def test_dash_s_response_file_string(self):
     create_file('response_file.txt', 'MyModule\n')
     create_file('response_file.json', '"MyModule"\n')
-    self.run_process([EMXX, test_file('hello_world.cpp'), '-sEXPORT_NAME=@response_file.txt'])
-    self.run_process([EMXX, test_file('hello_world.cpp'), '-sEXPORT_NAME=@response_file.json'])
+    self.run_process([EMXX, test_file('hello_world.cpp'), '-sMODULARIZE', '-sEXPORT_NAME=@response_file.txt'])
+    self.run_process([EMXX, test_file('hello_world.cpp'), '-sMODULARIZE', '-sEXPORT_NAME=@response_file.json'])
 
   def test_dash_s_response_file_list(self):
     create_file('response_file.txt', '_main\n_malloc\n')