Revert "[ADT] Drop llvm::Optional clang-specific optmization for trivially copyable types"

This reverts commit r346985.

It looks like one of the unittests also needs to be updated, reverting while I investigate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@346990 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed