Log Message:
regress/check-perms: add test for broken CHECK_PERMS_AUTOFIX

The variable CHECK_PERMS_AUTOFIX has been existing since 2006 but is not
used in any package. This may be because it is not helpful in any way.
When a package sets this variables to yes, the permission errors are not
silently fixed, but the build still fails instead. This behavior is not
useful in any way and thus needs to be fixed.

See https://mail-index.netbsd.org/tech-pkg/2019/08/thread1.html#021828