more mmap.has_madvise fixes on non-_POSIX platforms

--HG--
branch : winreg-audithooks
2 jobs for branch/winreg-audithooks in 8 minutes and 50 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Test
passed #179937
check_rpython_annotations

00:07:33

passed #179938
hpy_tests

00:08:49