Minor issue: exit in minishell behaves slightly different than in Bash

[linhtng]

Just for documentation, maybe not necessary to fix.

• minishell$ exit | exit
  Don't exit minishell but will print exit
  bash-3.2$ exit | exit
  bash-3.2$
  Bash doesn't exit bash and won't print exit.
  This is probably because bash print exit to STDERROR

• minishell$ exit > output
  Minishell: Exit and print exit to output.
  Bash: Printing exit to the shell and exit, output file is empty.

• bash-3.2$ exit -9223372036854775809
  exit
  bash: exit: -9223372036854775809: numeric argument required
  c2r1p6% echo $?
  255
  minishell$ exit -9223372036854775809
  exit
  c2r1p6% echo $?
  0