Add late load pdumper hooks so these can call into Lisp

Add late load pdumper hooks so these can call into Lisp

	* src/pdumper.h (pdumper_do_now_and_after_late_load): New function.
	* src/pdumper.c (dump_late_hooks, nr_dump_late_hooks): New static
	variables.
	(dump_metadata_for_pdumper): Add support for late load hooks.
	(pdumper_do_now_and_after_late_load_impl): New functions.
	(pdumper_load): Add support for late load hooks.
	* src/window.c (init_window_once): Register
	'init_window_once_for_pdumper' to be executed after late load.