Index: libcxx/include/module.modulemap
===================================================================
--- libcxx/include/module.modulemap
+++ libcxx/include/module.modulemap
@@ -550,6 +550,13 @@
   module __tree { header "__tree" export * }
   module __tuple { header "__tuple" export * }
   module __undef_macros { header "__undef_macros" export * }
+  module __memory {
+    // These can only be parsed when 'allocator' was defined.
+    textual header "__memory/allocator_traits.h"
+    textual header "__memory/allocation_guard.h"
+    umbrella "__memory"
+    export *
+  }
 
   module experimental {
     requires cplusplus11