Introduce four new code-completion hooks for C++:

  - after "using", show anything that can be a nested-name-specifier.
  - after "using namespace", show any visible namespaces or namespace aliases
  - after "namespace", show any namespace definitions in the current scope
  - after "namespace identifier = ", show any visible namespaces or
    namespace aliases



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@82251 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeCompletion/using.cpp b/test/CodeCompletion/using.cpp
new file mode 100644
index 0000000..7bef353
--- /dev/null
+++ b/test/CodeCompletion/using.cpp
@@ -0,0 +1,27 @@
+// RUN: clang-cc -fsyntax-only -code-completion-dump=1 %s -o - | FileCheck -check-prefix=CC1 %s &&
+// RUN: true
+
+namespace N4 {
+  namespace N3 { }
+}
+
+class N3;
+
+namespace N2 {
+  namespace I1 { }
+  namespace I4 = I1;
+  namespace I5 { }
+  namespace I1 { }
+  
+  void foo() {
+    int N3;
+    
+    // CHECK-CC1: I1 : 2
+    // CHECK-CC1: I4 : 2
+    // CHECK-CC1: I5 : 2
+    // CHECK-CC1: N2 : 3
+    // CHECK-CC1: N3 : 3
+    // CHECK-NEXT-CC1: N4 : 3
+    using
+    
+