libgomp.texi: Add OpenMP TR13 routines to @menu (commented out)

To keep track of missing routine documentation (both implemented and not),
the libgomp.texi file contains all non-OMPT routines as commented items
in @menu. This commit adds the routines added in TR13 as commented fixme
items.

libgomp/ChangeLog:

	* libgomp.texi (OpenMP Runtime Library Routines): Add TR13 routines
	to @menu (commented out).