Mark namespaces for user defined literals as 'inline'

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@192047 91177308-0d34-0410-b5e6-96231b3b80d8
Implement literal suffixes for compled

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@192048 91177308-0d34-0410-b5e6-96231b3b80d8
LWG Issue 2247: Implement type trait 'is_null_pointer'

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@192049 91177308-0d34-0410-b5e6-96231b3b80d8
Add tests making sure that optional<T>s can be compared at compile time; this functionality was enabled by N3789

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@192051 91177308-0d34-0410-b5e6-96231b3b80d8