Fix copy_from_string for unboxed arrays of records on systems with USE_DESC_RELATIVE_TO_ARRAY

The corresponding change in copy_string_to_graph was made in 41ebb64d.

Libraries/graph_copy/copy_string_to_graph.c

@@ -106,6 +106,11 @@ void remove_forwarding_pointers_from_string (Int *string_p,Int *end_forwarding_p
 						elem_desc=string_p[2];
 						string_p+=3;
 
+#if defined (USE_DESC_RELATIVE_TO_ARRAY)
+						if (elem_desc!=0)
+							elem_desc+=(Int)&__ARRAY__;
+#endif
+
 						if (elem_desc==0){
 						} else if (elem_desc==(Int)&INT+2
 #if ARCH_64