[index] Record C++17 global binding declarations

The global C++17 binding declarations should be indexed as variable symbols.

Differential Revision: https://reviews.llvm.org/D33920

llvm-svn: 305508
diff --git a/clang/lib/Index/IndexSymbol.cpp b/clang/lib/Index/IndexSymbol.cpp
index 0b20970..bf358a3 100644
--- a/clang/lib/Index/IndexSymbol.cpp
+++ b/clang/lib/Index/IndexSymbol.cpp
@@ -301,6 +301,10 @@
       Info.Kind = SymbolKind::TypeAlias;
       Info.Lang = SymbolLanguage::CXX;
       break;
+    case Decl::Binding:
+      Info.Kind = SymbolKind::Variable;
+      Info.Lang = SymbolLanguage::CXX;
+      break;
     default:
       break;
     }