heap_page_header  453 gc.c               struct heap_page_header header;
heap_page_header 1496 gc.c               start = (RVALUE*)((VALUE)page_body + sizeof(struct heap_page_header));
heap_page_header 1523 gc.c           	MEMMOVE(&heap_pages_sorted[hi+1], &heap_pages_sorted[hi], struct heap_page_header*, heap_allocated_pages - hi);