vim-patch:9.0.0904: various comment and indent flaws (#23498)

Problem:    Various comment and indent flaws.
Solution:   Improve comments and indenting.

88456cd3c4

Omit test_function_lists.vim change as that file is likely not
applicable to Nvim due to the existence of Nvim-only functions.

Co-authored-by: Bram Moolenaar <Bram@vim.org>

src/nvim/message.c

@@ -1250,6 +1250,7 @@ void wait_return(int redraw)
              || c == K_MOUSEDOWN || c == K_MOUSEUP
              || c == K_MOUSEMOVE);
     os_breakcheck();
+
     // Avoid that the mouse-up event causes visual mode to start.
     if (c == K_LEFTMOUSE || c == K_MIDDLEMOUSE || c == K_RIGHTMOUSE
         || c == K_X1MOUSE || c == K_X2MOUSE) {