Remove faulty optimisation from indentation calculation.
        * progmodes/cc-engine.el (c-guess-basic-syntax): Don't calculate
        search limit based on 2000 characters back from indent-point.
Fix bug #14540 with inaccurate doc string of pos-visible-in-window-p.

 src/window.c (Fpos_visible_in_window_p): Doc fix.