Ignore test case on Windows.
Ignore test case on Windows.

Windows is not #[cfg(target_thread_local)] and as such should link
to the external symbol. But it fails with:

    thread '<main>' panicked at 'assertion failed: `(left == right)` (left: `272246271`, right: `3`)', C:/bot/slave/auto-win-msvc-64-opt/build/src/test/run-pass/thread-local-extern-static.rs:24

GBGamer/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,graydon/rust,graydon/rust,graydon/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,GBGamer/rust,aidancully/rust,graydon/rust,graydon/rust