[libc++] Alphabetize and include-what-you-use. NFCI.

Differential Revision: https://reviews.llvm.org/D102781

NOKEYCHECK=True
GitOrigin-RevId: bfbd73f87d7b2c1140b43192cea6b7fbbfc35cd0
diff --git a/include/ios b/include/ios
index 0104b33..c58b983 100644
--- a/include/ios
+++ b/include/ios
@@ -211,8 +211,8 @@
 */
 
 #include <__config>
-#include <iosfwd>
 #include <__locale>
+#include <iosfwd>
 #include <system_error>
 
 #if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)