[libc++] Add tests verifying alphabetical order for several things.
These things are header #includes, CMakeLists.txt, and module.modulemap.
Differential Revision: https://reviews.llvm.org/D116958
NOKEYCHECK=True
GitOrigin-RevId: 42185ad870cb750ede2be38cf5ac5326ab9ac424
diff --git a/include/__debug b/include/__debug
index 4e80474..29c51b2 100644
--- a/include/__debug
+++ b/include/__debug
@@ -23,9 +23,9 @@
#endif
#if _LIBCPP_DEBUG_LEVEL >= 1 || defined(_LIBCPP_BUILDING_LIBRARY)
-# include <cstdlib>
-# include <cstdio>
# include <cstddef>
+# include <cstdio>
+# include <cstdlib>
#endif
#if _LIBCPP_DEBUG_LEVEL == 0