GLYPH_DEBUG fixes

GLYPH_DEBUG fixes

The following patches are for when GLYPH_DEBUG && !XASSERT.
* dispextern.h (trace_redisplay_p, dump_glyph_string):
* dispnew.c (flush_stdout):
* xdisp.c (dump_glyph_row, dump_glyph_matrix, dump_glyph):
Mark as externally visible.
* dispnew.c (check_window_matrix_pointers): Now static.
* dispnew.c (window_to_frame_vpos):
* xfns.c (unwind_create_frame):
* xterm.c (x_check_font): Remove unused local.
* scroll.c (CHECK_BOUNDS):
* xfaces.c (cache_fache): Rename local to avoid shadowing.
* xfns.c, w32fns.c (image_cache_refcount, dpyinfo_refcount): Now static.
* xdisp.c (check_window_end): Now a no-op if !XASSERTS.
(debug_first_unchanged_at_end_vpos, debug_last_unchanged_at_beg_vpos)
(debug_dvpos, debug_dy, debug_delta, debug_delta_bytes, debug_end_vpos):
Now static.
(debug_method_add): Use va_list and vsprintf rather than relying
on undefined behavior with wrong number of arguments.
(dump_glyph, dump_glyph_row, Fdump_glyph_matrix):
Don't assume ptrdiff_t and EMACS_INT are the same width as int.
In this code, it's OK to assume C99 behavior for ptrdiff_t formats
since we're not interested in debugging glyphs with old libraries.
* xfaces.c (cache_face): Move debugging code earlier; this pacifies
GCC 4.6.0's static checking.