Move helper classes into anonymous namespaces.

llvm-svn: 180642
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index ccad975..17e174e 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -1764,6 +1764,7 @@
   return handler.found(*O, ObjType);
 }
 
+namespace {
 struct ExtractSubobjectHandler {
   EvalInfo &Info;
   APValue &Obj;
@@ -1855,6 +1856,7 @@
   }
 };
 const AccessKinds ModifySubobjectHandler::AccessKind;
+} // end anonymous namespace
 
 /// Update the designated sub-object of an rvalue to the given value.
 static bool modifySubobject(EvalInfo &Info, const Expr *E,