[libc++] Granularize the rest of memory

Reviewed By: ldionne, #libc

Spies: vitalybuka, paulkirth, libcxx-commits, mgorny

Differential Revision: https://reviews.llvm.org/D132790

NOKEYCHECK=True
GitOrigin-RevId: d5e26775d089d099d02b168de8ea52179b1b1f75
diff --git a/include/regex b/include/regex
index 95a211f..e1799d9 100644
--- a/include/regex
+++ b/include/regex
@@ -770,9 +770,9 @@
 #include <__iterator/wrap_iter.h>
 #include <__locale>
 #include <__utility/move.h>
+#include <__utility/pair.h>
 #include <__utility/swap.h>
 #include <deque>
-#include <memory>
 #include <stdexcept>
 #include <string>
 #include <vector>