Squashed 'platforms/win32/plugins/' changes from 0c31c68..0f5d569

0f5d569 Exclude platform-dependent code from SqueakFFIPrims on win32.

git-subtree-dir: platforms/win32/plugins
git-subtree-split: 0f5d56986d95a8a7c5cc526cec7ef69270e527e7
Merge commit 'eb5bda44d904c68557286b55557ee8ab97690e6b'