Index: include/llvm/CodeGen/SelectionDAG.h
===================================================================
--- include/llvm/CodeGen/SelectionDAG.h
+++ include/llvm/CodeGen/SelectionDAG.h
@@ -215,7 +215,9 @@
   /// Tracks dbg_value information through SDISel.
   SDDbgInfo *DbgInfo;
 
+#ifndef LLVM_ENABLE_ABI_BREAKING_CHECKS
   uint16_t NextPersistentId = 0;
+#endif
 
 public:
   /// Clients of various APIs that cause global effects on
Index: include/llvm/CodeGen/SelectionDAGNodes.h
===================================================================
--- include/llvm/CodeGen/SelectionDAGNodes.h
+++ include/llvm/CodeGen/SelectionDAGNodes.h
@@ -426,9 +426,11 @@
   friend struct ilist_traits<SDNode>;
 
 public:
+#ifndef LLVM_ENABLE_ABI_BREAKING_CHECKS
   /// Unique and persistent id per SDNode in the DAG.
   /// Used for debug printing.
   uint16_t PersistentId;
+#endif
 
   //===--------------------------------------------------------------------===//
   //  Accessors