t/clang/expr-traits

Patch authored by David Abrahams.

These two expression traits (__is_lvalue_expr, __is_rvalue_expr) are used for
parsing code that employs certain features of the Embarcadero C++ compiler.

llvm-svn: 130122
diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp
index e738f0d..519bbaa 100644
--- a/clang/lib/AST/ExprConstant.cpp
+++ b/clang/lib/AST/ExprConstant.cpp
@@ -1061,6 +1061,10 @@
     return Success(E->getValue(), E);
   }
 
+  bool VisitExpressionTraitExpr(const ExpressionTraitExpr *E) {
+    return Success(E->getValue(), E);
+  }
+
   bool VisitChooseExpr(const ChooseExpr *E) {
     return Visit(E->getChosenSubExpr(Info.Ctx));
   }
@@ -2875,6 +2879,7 @@
   case Expr::CXXScalarValueInitExprClass:
   case Expr::UnaryTypeTraitExprClass:
   case Expr::BinaryTypeTraitExprClass:
+  case Expr::ExpressionTraitExprClass:
   case Expr::CXXNoexceptExprClass:
     return NoDiag();
   case Expr::CallExprClass: