Reland [libcxx]Put clang::trivial_abi on smart pointers

    Reviewed By: ldionne,EricWF

    Tags: #libcxx

    Differential Revision: https://reviews.llvm.org/D82490

Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 76887bc4c102a73669a95002d6a06121e7515e68
diff --git a/docs/index.rst b/docs/index.rst
index c60a72d..75d5b82 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -164,6 +164,7 @@
    DesignDocs/FileTimeType
    DesignDocs/FeatureTestMacros
    DesignDocs/ExtendedCXX03Support
+   DesignDocs/UniquePtrTrivialAbi
 
 * `<atomic> design <http://libcxx.llvm.org/atomic_design.html>`_
 * `<type_traits> design <http://libcxx.llvm.org/type_traits_design.html>`_