Remove unnecessary casts involving pointers.

Remove unnecessary casts involving pointers.

These casts are no longer needed now that we assume C89 or later,
since they involve casting to or from void *.
* alloc.c (make_pure_string, make_pure_c_string, pure_cons)
(make_pure_float, make_pure_vector):
* lisp.h (SAFE_ALLOCA, SAFE_ALLOCA_LISP):
* macros.c (Fstart_kbd_macro):
* menu.c (find_and_return_menu_selection):
* minibuf.c (read_minibuf_noninteractive):
* sysdep.c (closedir):
* xdisp.c (x_produce_glyphs):
* xfaces.c (compare_fonts_by_sort_order):
* xfns.c (x_real_positions, select_visual):
* xselect.c (x_stop_queuing_selection_requests)
(x_get_window_property, x_get_window_property_as_lisp_data):
* xterm.c (x_set_frame_alpha, x_find_modifier_meanings):
Remove unnecessary pointer casts.
* alloc.c (record_xmalloc): New function.
* lisp.h (record_xmalloc): New decl.
(SAFE_ALLOCA): Now takes just one arg -- the size -- and acts
more like a function.  This is because the pointer cast is not
needed.  All uses changed.
* print.c (print_string, print_error_message): Avoid length recalc.