Avoid excessive variable reuse in modularize function. NFC

I think this makes it a little easier to follow.

test/test_browser.py

@@ -4795,28 +4795,19 @@ def test_browser_run_from_different_directory(self):
 
   # Similar to `test_browser_run_from_different_directory`, but asynchronous because of `-sMODULARIZE`
   def test_browser_run_from_different_directory_async(self):
-    for args, creations in [
-      (['-sMODULARIZE'], [
-        'Module();',    # documented way for using modularize
-        'new Module();' # not documented as working, but we support it
-       ]),
-    ]:
-      print(args)
-      # compile the code with the modularize feature and the preload-file option enabled
-      self.compile_btest('browser_test_hello_world.c', ['-o', 'test.js', '-O3'] + args)
-      ensure_dir('subdir')
-      shutil.move('test.js', Path('subdir/test.js'))
-      shutil.move('test.wasm', Path('subdir/test.wasm'))
-      for creation in creations:
-        print(creation)
-        # Make sure JS is loaded from subdirectory
-        create_file('test-subdir.html', '''
-          <script src="subdir/test.js"></script>
-          <script>
-            %s
-          </script>
-        ''' % creation)
-        self.run_browser('test-subdir.html', '/report_result?0')
+    # compile the code with the modularize feature and the preload-file option enabled
+    self.compile_btest('browser_test_hello_world.c', ['-o', 'test.js', '-O3', '-sMODULARIZE'])
+    ensure_dir('subdir')
+    shutil.move('test.js', Path('subdir/test.js'))
+    shutil.move('test.wasm', Path('subdir/test.wasm'))
+    # Make sure JS is loaded from subdirectory
+    create_file('test-subdir.html', '''
+      <script src="subdir/test.js"></script>
+      <script>
+        Module();
+      </script>
+    ''')
+    self.run_browser('test-subdir.html', '/report_result?0')
 
   # Similar to `test_browser_run_from_different_directory`, but
   # also also we eval the initial code, so currentScript is not present. That prevents us

tools/link.py

@@ -2377,7 +2377,7 @@ def node_pthread_detection():
 def modularize():
   global final_js
   logger.debug(f'Modularizing, assigning to var {settings.EXPORT_NAME}')
-  src = read_file(final_js)
+  generated_js = read_file(final_js)
 
   # When targetting node and ES6 we use `await import ..` in the generated code
   # so the outer function needs to be marked as async.
@@ -2390,19 +2390,19 @@ def modularize():
     diagnostics.warning('emcc', 'EXPORT_NAME should not be named "config" when targeting Safari')
 
   if settings.MODULARIZE == 'instance':
-    src = '''
+    wrapper_funcion = '''
 export default async function init(moduleArg = {}) {
   var moduleRtn;
 
-%(src)s
+%(generated_js)s
 
   return await moduleRtn;
 }
 ''' % {
-      'src': src,
+      'generated_js': generated_js,
     }
   else:
-    src = '''
+    wrapper_funcion = '''
 %(maybe_async)sfunction(moduleArg = {}) {
   var moduleRtn;
 
@@ -2412,13 +2412,13 @@ def modularize():
 }
 ''' % {
       'maybe_async': async_emit,
-      'src': src,
+      'generated_js': generated_js,
     }
 
   if settings.MINIMAL_RUNTIME and not settings.PTHREADS:
     # Single threaded MINIMAL_RUNTIME programs do not need access to
     # document.currentScript, so a simple export declaration is enough.
-    src = '/** @nocollapse */ var %s = %s' % (settings.EXPORT_NAME, src)
+    src = '/** @nocollapse */ var %s = %s;' % (settings.EXPORT_NAME, wrapper_funcion)
   else:
     script_url_node = ''
     # When MODULARIZE this JS may be executed later,
@@ -2436,24 +2436,24 @@ def modularize():
       src = '''\
   var _scriptName = %(script_url)s;
   %(script_url_node)s
-  %(src)s
+  %(wrapper_funcion)s
 ''' % {
         'script_url': script_url,
         'script_url_node': script_url_node,
-        'src': src,
+        'wrapper_funcion': wrapper_funcion,
       }
     else:
       src = '''\
 var %(EXPORT_NAME)s = (() => {
   var _scriptName = %(script_url)s;
   %(script_url_node)s
-  return (%(src)s);
+  return (%(wrapper_funcion)s);
 })();
 ''' % {
         'EXPORT_NAME': settings.EXPORT_NAME,
         'script_url': script_url,
         'script_url_node': script_url_node,
-        'src': src,
+        'wrapper_funcion': wrapper_funcion,
       }
 
   # Given the async nature of how the Module function and Module object