page: added page_new_concat()

src/page.h

@@ -64,6 +64,15 @@ struct page {
 struct page *
 page_new_copy(const void *data, size_t size);
 
+/**
+ * Concatenates two pages to a new page.
+ *
+ * @param a the first page
+ * @param b the second page, which is appended
+ */
+struct page *
+page_new_concat(const struct page *a, const struct page *b);
+
 /**
  * Increases the reference counter.
  *