[test] cannot test stat on cygwin64 GH #1066

skip t/pmc/os.t 10 and 18. failing on cygwin64.
See http://perl514.cpanel.net/build/builders/parrot-cygwin64/builds/42/steps/shell_2/logs/stdio
[test] skip t/codingstd/pod_syntax.t if Capture::Tiny is missing

detected by my cygwin64 smoker, but this is a general problem