Some STL symbols are defined in inline namespaces. For example,
namespace std { inline namespace __cxx11 { typedef ... string; } }
Currently, this will be std::__cxx11::string; however, std::string is desired.
Inline namespaces are treated as transparent scopes. This
reflects the way they're most commonly used for lookup. Ideally we'd
include them, but at query time it's hard to find all the inline
namespaces to query: the preamble doesn't have a dedicated list.
I'd expand on this for inline namespaces a little, because it's non-obvious. e.g.
Conversely, I don't think you need to explicitly mention unscoped enums anymore, because the behavior for transparent scopes is the obvious one, and we shouldn't need any special code handling enums (see below suggestions).