jtreg unit/regression tests: Shell scripts under CYGWIN

[Brad Wetmore]

I know I'm approaching "Holy War" territory, but developers are starting 
to use Cygwin instead of MKS for their windows build environments.

Many of our existing test shell scripts contain the following pattern:

OS=`uname -s`
case "$OS" in
   SunOS | Linux )
     NULL=/dev/null
     PS=":"
     FS="/"
     TMP=/tmp
     ;;
   Windows_* )
     NULL=NUL
     PS=";"
     FS="\\"
     TMP="c:/temp"
     ;;
   * )
     echo "Unrecognized operating system!"
     exit 1;
     ;;
esac

This will fail on CYGWIN, as `uname -s` returns "CYGWIN_NT-5.1".  The 
fix is to update the Windows_* line to include CYGWIN:

   Windows_* | CYGWIN* )

Please do this when writing new tests or updating existing ones.

Thanks,

Brad