MDEV-19514 fixup: Optimize ibuf_merge_or_delete_for_page() calls

storage/innobase/buf/buf0buf.cc

@@ -3812,7 +3812,8 @@ loop:
 
   /* Delete possible entries for the page from the insert buffer:
   such can exist if the page belonged to an index which was dropped */
-  if (!recv_recovery_is_on())
+  if (page_id < page_id_t{SRV_SPACE_ID_UPPER_BOUND, 0} &&
+      !recv_recovery_is_on())
     ibuf_merge_or_delete_for_page(nullptr, page_id, zip_size);
 
   static_assert(FIL_PAGE_PREV + 4 == FIL_PAGE_NEXT, "adjacent");

storage/innobase/ibuf/ibuf0ibuf.cc

@@ -4203,6 +4203,10 @@ subsequently was dropped.
 void ibuf_merge_or_delete_for_page(buf_block_t *block, const page_id_t page_id,
                                    ulint zip_size)
 {
+	if (trx_sys_hdr_page(page_id)) {
+		return;
+	}
+
 	btr_pcur_t	pcur;
 #ifdef UNIV_IBUF_DEBUG
 	ulint		volume			= 0;
@@ -4217,11 +4221,8 @@ void ibuf_merge_or_delete_for_page(buf_block_t *block, const page_id_t page_id,
 	ut_ad(!block || page_id == block->page.id());
 	ut_ad(!block || block->page.state() == BUF_BLOCK_FILE_PAGE);
 	ut_ad(!block || block->page.status == buf_page_t::NORMAL);
-
-	if (trx_sys_hdr_page(page_id)
-	    || fsp_is_system_temporary(page_id.space())) {
-		return;
-	}
+	ut_ad(!trx_sys_hdr_page(page_id));
+	ut_ad(page_id < page_id_t(SRV_SPACE_ID_UPPER_BOUND, 0));
 
 	const ulint physical_size = zip_size ? zip_size : srv_page_size;