cppfiles.c (_cpp_pop_file_buffer): Return void.

cppfiles.c (_cpp_pop_file_buffer): Return void.

	* cppfiles.c (_cpp_pop_file_buffer): Return void.  Move
	file change and include code to _cpp_pop_buffer.
	* cpphash.h (struct pending_option): Predeclare.
	(struct cpp_reader): New member next_include_file.
	(_cpp_pop_file_buffer): Update.
	(_cpp_push_next_buffer): Update, rename.
	* cppinit.c (cpp_destroy): Free include chain and pending here.
	(cpp_finish_options): Simplify.
	(_cpp_push_next_buffer): Rename and clean up.
	* cpplib.c (cpp_pop_buffer): Move code from _cpp_pop_file_buffer.
	Clarify.
	* cppmacro.c (cpp_scan_nooutput): Set return_at_eof here.

From-SVN: r52621