https://gcc.gnu.org/ml/gcc-patches/2018-08/msg01149.html
	libcpp/
	* Makefile.in (TAGS_SOURCES): Remove cpp-id-data.h.
	* include/cpp-id-data.h: Delete.
	* internal.h: Include cpplib.h not cpp-id-data.h.
	gcc/
	* Makefile.in (CPP_ID_DATA_H): Delete.
	(CPP_INTERNAL_H): Don't add it.
	(GTFILES): Replace CPP_ID_DATA_H with CPPLIB_H.
	* gengtype.c (open_base_files): Replace cpp-id-data.h with cpplib.h

From-SVN: r263663