Implement C++ 'typeid' parsing and sema.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@59042 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index ce08560..86a2f29 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -437,6 +437,9 @@
     if (cast<ExplicitCastExpr>(this)->getTypeAsWritten()->isReferenceType())
       return LV_Valid;
     break;
+  case CXXTypeidExprClass:
+    // C++ 5.2.8p1: The result of a typeid expression is an lvalue of ...
+    return LV_Valid;
   case CXXThisExprClass:
     return LV_InvalidExpression;
   default: