200_fork.t panics on Windows

At least with Strawberry Perl 5.20 on Windows 7 x64. The message is:

    panic: attempt to copy freed scalar 23bad200 to 22bad28 at {something}/perl/lib/Test/Builder.pm line 2366.
Merge pull request #58 from nponeccop/patch-4

200_fork.t panics on Windows