Index: include/llvm/TableGen/Record.h
===================================================================
--- include/llvm/TableGen/Record.h
+++ include/llvm/TableGen/Record.h
@@ -267,8 +267,9 @@
   /// and IK_LastXXXInit be their own values, but that would degrade
   /// readability for really no benefit.
   enum InitKind : uint8_t {
-    IK_BitInit,
+    IK_First, // unused; silence a spurious warning
     IK_FirstTypedInit,
+    IK_BitInit,
     IK_BitsInit,
     IK_CodeInit,
     IK_DagInit,
@@ -284,9 +285,9 @@
     IK_StringInit,
     IK_VarInit,
     IK_VarListElementInit,
+    IK_VarBitInit,
     IK_LastTypedInit,
-    IK_UnsetInit,
-    IK_VarBitInit
+    IK_UnsetInit
   };
 
 private:
@@ -451,10 +452,10 @@
 };
 
 /// 'true'/'false' - Represent a concrete initializer for a bit.
-class BitInit : public Init {
+class BitInit final : public TypedInit {
   bool Value;
 
-  explicit BitInit(bool V) : Init(IK_BitInit), Value(V) {}
+  explicit BitInit(bool V) : TypedInit(IK_BitInit, BitRecTy::get()), Value(V) {}
 
 public:
   BitInit(const BitInit &) = delete;
@@ -470,6 +471,11 @@
 
   Init *convertInitializerTo(RecTy *Ty) const override;
 
+  Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                    unsigned Elt) const override {
+    llvm_unreachable("Illegal element reference off bit");
+  }
+
   Init *getBit(unsigned Bit) const override {
     assert(Bit < 1 && "Bit index out of range!");
     return const_cast<BitInit*>(this);
@@ -966,11 +972,12 @@
 };
 
 /// Opcode{0} - Represent access to one bit of a variable or field.
-class VarBitInit : public Init {
+class VarBitInit final : public TypedInit {
   TypedInit *TI;
   unsigned Bit;
 
-  VarBitInit(TypedInit *T, unsigned B) : Init(IK_VarBitInit), TI(T), Bit(B) {
+  VarBitInit(TypedInit *T, unsigned B)
+      : TypedInit(IK_VarBitInit, BitRecTy::get()), TI(T), Bit(B) {
     assert(T->getType() &&
            (isa<IntRecTy>(T->getType()) ||
             (isa<BitsRecTy>(T->getType()) &&
@@ -996,6 +1003,11 @@
   std::string getAsString() const override;
   Init *resolveReferences(Record &R, const RecordVal *RV) const override;
 
+  Init *resolveListElementReference(Record &R, const RecordVal *RV,
+                                    unsigned Elt) const override {
+    llvm_unreachable("Illegal element reference off bit");
+  }
+
   Init *getBit(unsigned B) const override {
     assert(B < 1 && "Bit index out of range!");
     return const_cast<VarBitInit*>(this);