nxstack and noexec_user_stack Compatibility

The noexec_user_stack and noexec_user_stack_log system variables are deprecated. However, if the variables remain in the /etc/system file, the protection of executable stacks is ensured by the following enforcement:

• If noexec_user_stack is set to 1, the value of nxstack remains enabled for all processes.

• If noexec_user_stack is set to 0, the value of nxstack becomes tagged-files.

• If noexec_user_stack_log is set to 1, log files of error messages are kept.

• If noexec_user_stack_log is set to 0, log files of error messages are not kept.