[index] 'using namespace' declarations in functions should record
the reference to the namespace

rdar://32323190


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@303555 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Index/IndexSymbol.cpp b/lib/Index/IndexSymbol.cpp
index a108f86..0b20970 100644
--- a/lib/Index/IndexSymbol.cpp
+++ b/lib/Index/IndexSymbol.cpp
@@ -61,6 +61,8 @@
   if (isa<ObjCTypeParamDecl>(D))
     return true;
 
+  if (isa<UsingDirectiveDecl>(D))
+    return false;
   if (!D->getParentFunctionOrMethod())
     return false;