c++/modules: Update lang_decl_bool streaming

c++/modules: Update lang_decl_bool streaming

The set of lang_decl flags that we were streaming had gotten out of sync
with the current list; update them.

One notable change is that anticipated_p, which had previously been
deliberately skipped, is now only used for DECL_OMP_PRIVATIZED_MEMBER,
and so should probably be streamed as well.

gcc/cp/ChangeLog:

	* module.cc (trees_out::lang_decl_bools): Update list of flags.
	(trees_in::lang_decl_bools): Likewise.

Reviewed-by: Jason Merrill <jason@redhat.com>
Signed-off-by: Nathaniel Shead <nathanieloshead@gmail.com>