Revert "Win: Use FILE_RENAME_FLAG_POSIX_SEMANTICS for std::fs::rename if available"

This reverts commit 1e414f1.

Author: nabijaczleweli

library/std/src/fs.rs

@@ -2446,14 +2446,12 @@ pub fn symlink_metadata<P: AsRef<Path>>(path: P) -> io::Result<Metadata> {
 /// # Platform-specific behavior
 ///
 /// This function currently corresponds to the `rename` function on Unix
-/// and the `SetFileInformationByHandle` function on Windows.
+/// and the `MoveFileEx` function with the `MOVEFILE_REPLACE_EXISTING` flag on Windows.
 ///
 /// Because of this, the behavior when both `from` and `to` exist differs. On
 /// Unix, if `from` is a directory, `to` must also be an (empty) directory. If
-/// `from` is not a directory, `to` must also be not a directory. The behavior
-/// on Windows is the same on Windows 10 1607 and higher if `FileRenameInfoEx`
-/// is supported by the filesystem; otherwise, `from` can be anything, but
-/// `to` must *not* be a directory.
+/// `from` is not a directory, `to` must also be not a directory. In contrast,
+/// on Windows, `from` can be anything, but `to` must *not* be a directory.
 ///
 /// Note that, this [may change in the future][changes].
 ///