commit bab74864168bb5e28ecbc0294fe1095d8da7f569
Author: Reid Kleckner <rnk@google.com>
Date:   Mon Feb 1 15:18:42 2021 -0800

    Disable CFI in __get_elem to allow casting a pointer to uninitialized memory
    
    Fixes usage of shared_ptr with CFI enabled, which is llvm.org/pr48993.
    
    Differential Revision: https://reviews.llvm.org/D95827

diff --git a/libcxx/include/memory b/libcxx/include/memory
index a00916c8c03f..39d0f5bee6a5 100644
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -2647,7 +2647,7 @@ private:
             _Alloc *__alloc = reinterpret_cast<_Alloc*>(__first);
             return __alloc;
         }
-        _Tp* __get_elem() _NOEXCEPT {
+        _LIBCPP_NO_CFI _Tp* __get_elem() _NOEXCEPT {
             _CompressedPair *__as_pair = reinterpret_cast<_CompressedPair*>(__blob_);
             typename _CompressedPair::_Base2* __second = _CompressedPair::__get_second_base(__as_pair);
             _Tp *__elem = reinterpret_cast<_Tp*>(__second);