gdb/

gdb/
	* symfile.c (objfilep): New typedef and new DEF_VEC_P.
	(reread_symbols): Remove variable reread_one, new variables
	new_objfiles, all_cleanups and ix.  Use new_objfiles instead of
	reread_one.  Push changed objfiles to new_objfiles, call
	observer_notify_new_objfile for them later.