Add Sema support for C++ classes.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@52956 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index c87e615..0e1a8ee 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -116,6 +116,8 @@
   KnownFunctionIDs[id_vprintf]   = &IT.get("vprintf");
 
   TUScope = 0;
+  if (getLangOptions().CPlusPlus)
+    FieldCollector.reset(new CXXFieldCollector());
 }
 
 /// ImpCastExprToType - If Expr is not of type 'Type', insert an implicit cast.