Silence clang 13 -Wunused-but-set-variable for Bison

sql/CMakeLists.txt

 # Copyright (c) 2006, 2014, Oracle and/or its affiliates.
-# Copyright (c) 2010, 2018, MariaDB Corporation
+# Copyright (c) 2010, 2022, MariaDB Corporation.
 # 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -146,6 +146,13 @@ SET (SQL_SOURCE
                ${MYSYS_LIBWRAP_SOURCE}
 )
 
+IF(CMAKE_C_COMPILER_ID MATCHES "Clang" AND
+   NOT CMAKE_C_COMPILER_VERSION VERSION_LESS "13.0.0")
+  ADD_COMPILE_FLAGS(${CMAKE_CURRENT_BINARY_DIR}/sql_yacc.cc
+    ${CMAKE_CURRENT_BINARY_DIR}/sql_yacc_ora.cc
+    COMPILE_FLAGS "-Wno-unused-but-set-variable")
+ENDIF()
+
 IF (CMAKE_SYSTEM_NAME MATCHES "Linux" OR
     CMAKE_SYSTEM_NAME MATCHES "Windows" OR
     CMAKE_SYSTEM_NAME MATCHES "SunOS" OR

storage/innobase/CMakeLists.txt

@@ -371,6 +371,11 @@ IF(MSVC)
   # on generated file.
   TARGET_COMPILE_OPTIONS(innobase PRIVATE "/wd4065")
 ENDIF()
+IF(CMAKE_C_COMPILER_ID MATCHES "Clang" AND
+   NOT CMAKE_C_COMPILER_VERSION VERSION_LESS "13.0.0")
+  ADD_COMPILE_FLAGS(pars/pars0grm.cc fts/fts0pars.cc
+    COMPILE_FLAGS "-Wno-unused-but-set-variable")
+ENDIF()
 
 IF(NOT (PLUGIN_INNOBASE STREQUAL DYNAMIC))
   ADD_SUBDIRECTORY(${CMAKE_SOURCE_DIR}/extra/mariabackup ${CMAKE_BINARY_DIR}/extra/mariabackup)