MSVC: implement fsync()
diff --git a/compat/posix-shims/unistd.h b/compat/posix-shims/unistd.h
index da46096..c739299 100644
--- a/compat/posix-shims/unistd.h
+++ b/compat/posix-shims/unistd.h
@@ -31,6 +31,7 @@
#define chdir _chdir
#define isatty _isatty
#define lseek _lseek
+#define fsync _commit
/* read, write, and close are NOT being #defined here, because while there are file handle specific versions for Windows, they probably don't work for sockets. You need to look at your app and consider whether to call e.g. closesocket(). */
#ifdef _WIN64