Test flake in bstr.dart

[timsneath]

Hey @timsneath, this test is flaky:
https://github.com/timsneath/win32/blob/cc9933f2216b5da247227a050aa3e2f21421abaf/test/bstr_test.dart#L23-L26

If you run this test several times on your computer, you will notice that it sometimes fails.

Originally posted by @halildurmus in #406 (comment)

[timsneath]

Yuck - that's annoying. How strange that it's intermittent. I'll take a look.

The BSTR data type is documented here, for my ease of reference later:
https://docs.microsoft.com/en-us/previous-versions/windows/desktop/automat/bstr

[timsneath]

Doh! The clue is in my own comment: "A BSTR should end with a word-length null terminator."

And then I go and allocate a DWORD. 🤦

[halildurmus]

Oops 😂

[timsneath]

Should be fixed in 9bc07e4