rt: Make |align| a member of the shape glue class instead of threading it through every function

Author: pcwalton

src/rt/rust_gc.cpp

@@ -121,9 +121,9 @@ gc::mark(std::vector<root> &roots) {
         shape::arena arena;
         shape::type_param *params = shape::type_param::from_tydesc(ri->tydesc,
                                                                    arena);
-        shape::log log(task, ri->tydesc->shape, params,
+        shape::log log(task, true, ri->tydesc->shape, params,
                        ri->tydesc->shape_tables, ri->data, std::cerr);
-        log.walk(true);
+        log.walk();
         DPRINT("\n");
 
         ++ri;