Add CK_NullToMemberPointer and CK_BaseToDerivedMemberPointer cast kinds. Make -ast-dump print out the cast kinds of cast expressions.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@79787 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExprCXX.cpp b/lib/Sema/SemaExprCXX.cpp
index 7540dff..0434f30 100644
--- a/lib/Sema/SemaExprCXX.cpp
+++ b/lib/Sema/SemaExprCXX.cpp
@@ -1014,12 +1014,13 @@
     ImpCastExprToType(From, ToType);
     break;
 
-  case ICK_Pointer_Member:
-    if (CheckMemberPointerConversion(From, ToType))
-      return true;
-    ImpCastExprToType(From, ToType);
-    break;
-
+    case ICK_Pointer_Member: {
+      CastExpr::CastKind Kind = CastExpr::CK_Unknown;
+      if (CheckMemberPointerConversion(From, ToType, Kind))
+        return true;
+      ImpCastExprToType(From, ToType, Kind);
+      break;
+    }
   case ICK_Boolean_Conversion:
     FromType = Context.BoolTy;
     ImpCastExprToType(From, FromType);