re PR other/59055 (gcc.texinfo warnings)

	PR other/59055
	* doc/bugreport.texi (Bugs): Remove nodes pointing to the
	nirvana.
	* doc/gcc.texi (Service): Update description in the @menu
	* doc/invoke.texi (Option Summary): Remove misplaced and
	duplicated @menu.

From-SVN: r209303