Table number > MAX_TABLES causes overflow of table_map at main.join test

Caught by UBSAN:

/home/buildbot/buildbot/build/mariadb-10.5.28/sql/sql_base.h:357:29: runtime error: shift exponent 64 is too large for 64-bit type 'long long unsigned int'

This happens inside setup_table_map() when tablenr==64 while table->map is a 64-bit integer, so there's an overflow.

Needs to figure out why there's no error generated when tablenr==MAX_TABLES and optionally add DBUG_ASSERT(tablenr < MAX_TABLES) to setup_table_map() to be able to catch such situations without running UBSAN.