* diagnostic.c (trim_filename, fancy_abort): Moved here from
	rtl.c.
	(fatal_function, set_fatal_function): Removed.
	(fatal): Don't prepare for or call the fatal_function.
	(diagnostic_lock, error_recursion): New.
	(diagnostic_for_decl, report_diagnostic): Guard against
	re-entering the error reporting routines.
	(fancy_abort): Assume function is not NULL.

	* errors.c (fancy_abort): New.  Assume function is not NULL.
	* tradcpp.c (fancy_abort): Assume function is not NULL.

	* system.h: Provide default definition of __FUNCTION__.
	* rtl.h: Use __FUNCTION__ not __PRETTY_FUNCTION__ throughout.
	Always use __FUNCTION__ in definition of abort.
	* tree.h: Likewise.
	* varray.h: Likewise.
	* toplev.h: Likewise.  Don't prototype set_fatal_function.

From-SVN: r35170