Remove unused code from __functional_base. NFC.
Patch from Arthur O'Dwyer.
`__user_alloc_construct_impl` is used by <experimental/memory_resource>, but
this `__user_alloc_construct` is never used.
Also, `<experimental/memory_resource>` doesn't need a full definition of
`std::tuple`; just the forward declaration in `<__tuple>` will suffice.
Reviewed as https://reviews.llvm.org/D46806
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@334069 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed
