does not work for narrowed buffers

[edgimar]

When a buffer is narrowed to a region that doesn't include the first line, then it is not possible to scroll the narrowed region down from the top of the buffer.

To Reproduce

1. open a document
2. highlight a region of the document not including the first line
3. execute M-x narrow-to-region
4. try to scroll down from the top -- not possible.

Emacs version

GNU Emacs 28.2 (build 2, x86_64-w64-mingw32) of 2022-09-13.