There are two flags in the LuaJIT useful for debugging and runtime
configuration purposes: `-j` and `-b`. However, if you want to
check the same Lua code from the Tarantool, you will need to make
some adjustments in the script itself, as those flags are not
present in the Tarantool's CLI.

This patch introduces those flags to the Tarantool, so debugging is
much more convenient now. Flags are working the same as they do in
the LuaJIT.

Closes #5541

NO_DOC=http://luajit.org/running.html#opt_b
NO_DOC=http://luajit.org/running.html#opt_j