[libc++] Update with LWG issue number for shared-ptr constructor

Author: ldionne

libcxx/docs/Status/Cxx2cIssues.csv

@@ -65,4 +65,5 @@
 "`3343 <https://wg21.link/LWG3343>`__","Ordering of calls to ``unlock()`` and ``notify_all()`` in Effects element of ``notify_all_at_thread_exit()`` should be reversed","Not Yet Adopted","|Complete|","16.0",""
 "XXXX","","The sys_info range should be affected by save","Not Yet Adopted","|Complete|","19.0"
 "`4071 <https://wg21.link/LWG4071>`__","","``reference_wrapper`` comparisons are not SFINAE-friendly","Not Yet Adopted","|Complete|","19.0"
+"`4110 <https://wg21.link/LWG4110>`__","","``shared_ptr(nullptr_t, Deleter)`` is overconstrained, breaking some sensible deleters","Not Yet Adopted","|Complete|","19.0"
 "","","","","",""

libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter.pass.cpp

@@ -117,7 +117,7 @@ int main(int, char**)
 
 #if TEST_STD_VER >= 14
     {
-      // See https://github.com/llvm/llvm-project/pull/93071#issuecomment-2158494851
+      // LWG 4110
       auto deleter = [](auto pointer) { delete pointer; };
       std::shared_ptr<int> p(new int, deleter);
     }

libcxx/test/std/utilities/memory/util.smartptr/util.smartptr.shared/util.smartptr.shared.const/pointer_deleter_allocator.pass.cpp

@@ -167,7 +167,7 @@ int main(int, char**)
 
 #if TEST_STD_VER >= 14
     {
-      // See https://github.com/llvm/llvm-project/pull/93071#issuecomment-2158494851
+      // LWG 4110
       auto deleter = [](auto pointer) { delete pointer; };
       std::shared_ptr<int> p(new int, deleter, std::allocator<int>());
     }