Some name-lookup-related fixes, from Piotr Rak!

- Changes Lookup*Name functions to return NamedDecls, instead of
Decls. Unfortunately my recent statement that it will simplify lot of
code, was not quite right, but it simplifies some...
- Makes MergeLookupResult SmallPtrSet instead of vector, following
Douglas suggestions.
- Adds %qN format for printing qualified names to Diagnostic.
- Avoids searching for using-directives in Scopes, which are not
DeclScope, during unqualified name lookup.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63739 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Basic/Diagnostic.cpp b/lib/Basic/Diagnostic.cpp
index 5b1145f..2429bdd 100644
--- a/lib/Basic/Diagnostic.cpp
+++ b/lib/Basic/Diagnostic.cpp
@@ -608,6 +608,7 @@
     }
     case Diagnostic::ak_qualtype:
     case Diagnostic::ak_declarationname:
+    case Diagnostic::ak_nameddecl:
       OutStr.push_back('\'');
       getDiags()->ConvertArgToString(getArgKind(ArgNo), getRawArg(ArgNo),
                                      Modifier, ModifierLen,