MDEV-21548 Explicitly declare sql_bultins library STATIC.

Someone tried -DBUILD_SHARED_LIBS:BOOL=ON. This did not work well

sql/CMakeLists.txt

@@ -289,7 +289,7 @@ IF(MSVC AND NOT WITHOUT_DYNAMIC_PLUGINS)
   SET_TARGET_PROPERTIES(mysqld_import_lib PROPERTIES IMPORTED_LOCATION ${MYSQLD_LIB})
 ENDIF()
 
-ADD_LIBRARY( sql_builtins  ${CMAKE_CURRENT_BINARY_DIR}/sql_builtin.cc)
+ADD_LIBRARY(sql_builtins STATIC ${CMAKE_CURRENT_BINARY_DIR}/sql_builtin.cc)
 TARGET_LINK_LIBRARIES(sql_builtins ${MYSQLD_STATIC_PLUGIN_LIBS})
 
 MYSQL_ADD_EXECUTABLE(mysqld ${MYSQLD_SOURCE} DESTINATION ${INSTALL_SBINDIR} COMPONENT Server)