Issue #16714: use 'raise' exceptions, don't 'throw'.

Patch by Serhiy Storchaka.

Lib/pkgutil.py

@@ -502,7 +502,7 @@ def find_loader(fullname):
         return importlib.find_loader(fullname, path)
     except (ImportError, AttributeError, TypeError, ValueError) as ex:
         # This hack fixes an impedance mismatch between pkgutil and
-        # importlib, where the latter throws other errors for cases where
+        # importlib, where the latter raises other errors for cases where
         # pkgutil previously threw ImportError
         msg = "Error while finding loader for {!r} ({}: {})"
         raise ImportError(msg.format(fullname, type(ex), ex)) from ex