cpphash.h: Update comments.

cpphash.h: Update comments.

	* cpphash.h: Update comments.
	(cpp_context): Update.
	(spec_nodes): Remove n__Pragma.
	* cppinit.c (cpp_create_reader): Update.
	(builtin_array): Add _Pragma.
	* cpplib.h: Update comments.
	(NODE_DISABLED, BT_PRAGMA): New.
	(cpp_start_lookahead, cpp_stop_lookahead): Remove prototypes.
	* cppmacro.c (struct cpp_macro): Remove disabled.
	(builtin_macro): Return int, handle _Pragma, push the new token
	on the context stack.
	(funlike_invocation_p): Unconstify, update.
	(enter_macro_context): Handle builtins here.
	(replace_args, push_token_context, push_ptoken_context):
	Update for prototype changes.
	(_cpp_pop_context): Update.
	(cpp_get_token): Don't handle buitins, nor _Pragma here.
	(cpp_sys_macro_p): Update.
	(_cpp_free_definition): Clear disabled flag.
	(_cpp_create_definition): Upate.
	* cppmain.c: Update comments.

From-SVN: r45948