ignore 'using' directive in CodeGenFunction::EmitDecl(). this fixes PR5085

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@84255 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp
index 7feff83..cc0696a 100644
--- a/lib/CodeGen/CGDecl.cpp
+++ b/lib/CodeGen/CGDecl.cpp
@@ -37,6 +37,7 @@
   case Decl::Enum:      // enum X;
   case Decl::EnumConstant: // enum ? { X = ? }
   case Decl::CXXRecord: // struct/union/class X; [C++]
+  case Decl::UsingDirective: // using X; [C++]
     // None of these decls require codegen support.
     return;