re PR c/52977 (internal compiler error: Segmentation fault with `-x c-header' or `-x cxx-header' option)

	PR middle-end/52977
	* tree.h (VECTOR_CST_NELTS): Use part number of types again.
	(struct tree_vector): Adjust GTY length.
	* tree.c (make_vector_stat): Don't set VECTOR_CST_NELTS.

	* gengtype.c (struct walk_type_data): Add in_record_p and loopcounter
	members.
	(walk_type, <TYPE_POINTER, TYPE_ARRAY>): Handle case where our
	caller emitted the length calulation already.
	(walk_type, <TYPE_UNION, TYPE_STRUCT>): Emit length calculations

From-SVN: r186593