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

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

NOKEYCHECK=True
GitOrigin-RevId: bfbd73f87d7b2c1140b43192cea6b7fbbfc35cd0
diff --git a/include/mutex b/include/mutex
index babb2b4..a23c213 100644
--- a/include/mutex
+++ b/include/mutex
@@ -188,14 +188,14 @@
 
 #include <__config>
 #include <__mutex_base>
+#include <__threading_support>
 #include <cstdint>
 #include <functional>
 #include <memory>
 #ifndef _LIBCPP_CXX03_LANG
-#include <tuple>
+# include <tuple>
 #endif
 #include <version>
-#include <__threading_support>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header