MDEV-27476 heap-use-after-free in buf_pool_t::is_block_field()

This follows up commit 017d1b8.
In commit aaef2e1 (MDEV-27058)
some more problematic debug assertions were added.

btr_search_update_block_hash_info(), trx_purge_truncate_history():
Use simpler assertions to check that an uncompressed page is present.

Author: dr-m

storage/innobase/btr/btr0sea.cc

@@ -2,7 +2,7 @@
 
 Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2008, Google Inc.
-Copyright (c) 2017, 2021, MariaDB Corporation.
+Copyright (c) 2017, 2022, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted by
 Google, Inc. Those modifications are gratefully acknowledged and are described
@@ -412,7 +412,7 @@ btr_search_update_block_hash_info(btr_search_t* info, buf_block_t* block)
 	ut_ad(block->page.lock.have_x() || block->page.lock.have_s());
 
 	info->last_hash_succ = FALSE;
-	ut_ad(buf_pool.is_uncompressed(block));
+	ut_ad(block->page.frame);
 	ut_ad(info->magic_n == BTR_SEARCH_MAGIC_N);
 
 	if ((block->n_hash_helps > 0)

storage/innobase/trx/trx0purge.cc

@@ -703,8 +703,8 @@ TRANSACTIONAL_TARGET static void trx_purge_truncate_history()
       if (bpage->id().space() == space.id &&
           bpage->oldest_modification() != 1)
       {
+        ut_ad(bpage->frame);
         auto block= reinterpret_cast<buf_block_t*>(bpage);
-        ut_ad(buf_pool.is_uncompressed(block));
         if (!bpage->lock.x_lock_try())
         {
           /* Let buf_pool_t::release_freed_page() proceed. */