Implement dereferencing of pointers-to-member.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@63983 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index d627ab0..89fdbe3 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -496,6 +496,12 @@
         BinOp->getOpcode() == BinaryOperator::Comma)
       return BinOp->getRHS()->isLvalue(Ctx);
 
+    // C++ [expr.mptr.oper]p6
+    if ((BinOp->getOpcode() == BinaryOperator::PtrMemD ||
+         BinOp->getOpcode() == BinaryOperator::PtrMemI) &&
+        !BinOp->getType()->isFunctionType())
+      return BinOp->getLHS()->isLvalue(Ctx);
+
     if (!BinOp->isAssignmentOp())
       return LV_InvalidExpression;