[ruby/mmtk] Add a 32 byte heap for allocating smaller objects

ruby/mmtk@c4cca6c1c3

Author: peterzhu2118

gc/mmtk/mmtk.c

@@ -472,11 +472,11 @@ void rb_gc_impl_set_params(void *objspace_ptr) { }
 
 static VALUE gc_verify_internal_consistency(VALUE self) { return Qnil; }
 
-#define MMTK_HEAP_COUNT 5
+#define MMTK_HEAP_COUNT 6
 #define MMTK_MAX_OBJ_SIZE 640
 
 static size_t heap_sizes[MMTK_HEAP_COUNT + 1] = {
-    40, 80, 160, 320, MMTK_MAX_OBJ_SIZE, 0
+    32, 40, 80, 160, 320, MMTK_MAX_OBJ_SIZE, 0
 };
 
 void