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

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

NOKEYCHECK=True
GitOrigin-RevId: bfbd73f87d7b2c1140b43192cea6b7fbbfc35cd0
diff --git a/include/exception b/include/exception
index fd0cb22..3405a42 100644
--- a/include/exception
+++ b/include/exception
@@ -76,8 +76,8 @@
 
 */
 
-#include <__config>
 #include <__availability>
+#include <__config>
 #include <__memory/addressof.h>
 #include <cstddef>
 #include <cstdlib>