os.renameatW: Handle OBJECT_NAME_COLLISION from NtSetInformationFile

Partially addresses #16374

lib/std/os.zig

@@ -2674,6 +2674,7 @@ pub fn renameatW(
         .OBJECT_NAME_NOT_FOUND => return error.FileNotFound,
         .OBJECT_PATH_NOT_FOUND => return error.FileNotFound,
         .NOT_SAME_DEVICE => return error.RenameAcrossMountPoints,
+        .OBJECT_NAME_COLLISION => return error.PathAlreadyExists,
         else => return windows.unexpectedStatus(rc),
     }
 }