Rework cairo image support to improve consistency (Bug#35871)

Rework cairo image support to improve consistency (Bug#35871)

* src/dispextern.h (Emacs_Pix_Container) [USE_CAIRO]: New struct.  Also used
as aliases of Emacs_Pixmap and Emacs_Pix_Context.
(x_kill_gs_process) [USE_CAIRO]: #ifdef out extern.
(RGB_PIXEL_COLOR) [USE_CAIRO]: Define as unsigned long.

* src/image.c: Include stdint.h.  On cairo, remove existing image support
code, use non-X11-specific code for XBM/XPM, and remove POSTSCRIPT support.
(PUT_PIXEL): New macro.  Use it instead of XPutPixel when not specific to X11.
(GET_PIXEL, NO_PIXMAP, PIX_MASK_RETAIN, PIX_MASK_DRAW)
(RGB_TO_ULONG, ARGB_TO_ULONG, RED_FROM_ULONG)
(GREEN_FROM_ULONG, BLUE_FROM_ULONG, RED16_FROM_ULONG)
(GREEN16_FROM_ULONG, BLUE16_FROM_ULONG)	[USE_CAIRO]: New macros.
(image_create_pix_container, image_pix_container_put_pixel)
(image_pix_context_get_pixel, image_pix_container_create_from_bitmap_data)
(cr_create_cr_surface_from_image) [USE_CAIRO]: New functions.
(image_create_x_image_and_pixmap_1, image_destroy_x_image)
(image_check_image_size): Extract X11-specific code from here ...
(x_create_x_image_and_pixmap, x_destroy_x_image)
(x_check_image_size) [HAVE_X_WINDOWS]: ... to here.
(x_create_bitmap_mask) [HAVE_X_WINDOWS]: Use them.  Inline specialized version
of four_corners_best.
(prepare_image_for_display, image_clear_image_1, image_destroy_x_image)
(gui_put_x_image, image_put_x_image, image_get_x_image, image_unget_x_image)
(Create_Pixmap_From_Bitmap_Data, lookup_rgb_color)
(image_to_emacs_colors) [USE_CAIRO]: Add cairo support.
(image_background, png_load_body) [USE_CAIRO]: Use image_alloc_image_color for
img->background.
(image_sync_to_pixmaps) [USE_CAIRO]: #ifdef out function.
(Create_Pixmap_From_Bitmap_Data) [HAVE_X_WINDOWS]: Move image_check_image_size
call from here ...
(xbm_load_image): ... to here.
(xpm_load_image):
(image_build_heuristic_mask, pbm_load, gif_load) [USE_CAIRO]: Use
lookup_rgb_color for argument of PUT_PIXEL.
(image_pixmap_draw_cross) [HAVE_X_WINDOWS || USE_CAIRO]: New function.
(image_disable_image) [HAVE_X_WINDOWS || USE_CAIRO]: Use it.
(CrossForeground) [!HAVE_NTGUI && !HAVE_NS]: New macro.
(image_disable_image) [!HAVE_NTGUI && !HAVE_NS]: Use it.

* src/xterm.c (handle_one_xevent) <ClientMessage> [USE_CAIRO]: #ifdef out
x_kill_gs_process call.
(x_free_pixmap) [USE_CAIRO]: Free Emacs_Pix_Container and data it contains.