importlib: Add iter_modules support to BuiltinLoader

Author: Maxwell175

Lib/importlib/_bootstrap.py

@@ -798,6 +798,13 @@ def is_package(cls, fullname):
         """Return False as built-in modules are never packages."""
         return False
 
+    @classmethod
+    def iter_modules(cls, prefix=''):
+        """Yield all built-in modules matching the given prefix."""
+        for name in sys.builtin_module_names:
+            if name.startswith(prefix):
+                yield name, False
+
     load_module = classmethod(_load_module_shim)