* Makefile (gccbug): New target.
	(doc): Depend on it.
	* gcc.texi (Bugs): Link subnodes.
	(gccbug): New node.
	* gccbug.in (CATEGORIES): Remove gc, host, profiling, libgcc.
	Document severities, priorities, and classes in bug form.
	* ChangeLog: Replace leading spaces with tabs.

From-SVN: r32915