Use dump_function_name rather than emit <built-in>

2016-12-07  Martin Jambor  <mjambor@suse.cz>

	PR c++/78589
	* error.c (dump_decl): Use dump_function_name to dump
	!DECL_LANG_SPECIFIC function decls with no or self-referencing
	abstract origin.

From-SVN: r243344

gcc/cp/ChangeLog

+2016-12-07  Martin Jambor  <mjambor@suse.cz>
+
+	PR c++/78589
+	* error.c (dump_decl): Use dump_function_name to dump
+	!DECL_LANG_SPECIFIC function decls with no or self-referencing
+	abstract origin.
+
 2016-12-07  Nathan Sidwell  <nathan@acm.org>
 
 	* pt.c (tsubst <{NON,}TYPE_ARGUMENT_PACK>: Simplify control flow

gcc/cp/error.c

@@ -1216,10 +1216,11 @@ dump_decl (cxx_pretty_printer *pp, tree t, int flags)
     case FUNCTION_DECL:
       if (! DECL_LANG_SPECIFIC (t))
 	{
-	  if (DECL_ABSTRACT_ORIGIN (t))
+	  if (DECL_ABSTRACT_ORIGIN (t)
+	      && DECL_ABSTRACT_ORIGIN (t) != t)
 	    dump_decl (pp, DECL_ABSTRACT_ORIGIN (t), flags);
 	  else
-	    pp_string (pp, M_("<built-in>"));
+	    dump_function_name (pp, t, flags);
 	}
       else if (DECL_GLOBAL_CTOR_P (t) || DECL_GLOBAL_DTOR_P (t))
 	dump_global_iord (pp, t);