Compare symbols by their name not by their address to prevent non-determinism.

src/object.c

@@ -427,6 +427,8 @@ int oopcmp(oop a, oop b)
             }
             case String:
                 return strcmp(get(a, String, value), get(b, String, value));
+	    case Symbol:
+		return strcmp(get(a, Symbol, name), get(b, Symbol, name));
             default: {
                 intptr_t l= (intptr_t)a, r= (intptr_t)b;
                 if (l < r) return -1;