TableGen: Remove OpInit::Fold

[nhaehnle]

Summary

Virtual dispatch is not actually used anywhere.

Change-Id: I9829c5c59920ea27fb9bc17f1442156a3bb09a65

llvm/trunk/include/llvm/TableGen/Record.h

public:
   }
 
   // Clone - Clone this operator, replacing arguments with the new list
   virtual OpInit *clone(ArrayRef<Init *> Operands) const = 0;
 
   virtual unsigned getNumOperands() const = 0;
   virtual Init *getOperand(unsigned i) const = 0;
 
-  // Fold - If possible, fold this to a simpler init.  Return this if not
-  // possible to fold.
-  virtual Init *Fold(Record *CurRec) const = 0;
-
   Init *getBit(unsigned Bit) const override;
 };
 
 /// !op (X) - Transform an init.
 ///
 class UnOpInit : public OpInit, public FoldingSetNode {
 public:
   enum UnaryOp : uint8_t { CAST, HEAD, TAIL, SIZE, EMPTY };
Init *getOperand(unsigned i) const override {
     return getOperand();
   }
 
   UnaryOp getOpcode() const { return (UnaryOp)Opc; }
   Init *getOperand() const { return LHS; }
 
   // Fold - If possible, fold this to a simpler init.  Return this if not
   // possible to fold.
-  Init *Fold(Record *CurRec) const override;
+  Init *Fold(Record *CurRec) const;
 
   Init *resolveReferences(Resolver &R) const override;
 
   std::string getAsString() const override;
 };
 
 /// !op (X, Y) - Combine two inits.
 class BinOpInit : public OpInit, public FoldingSetNode {
public:
   }
 
   BinaryOp getOpcode() const { return (BinaryOp)Opc; }
   Init *getLHS() const { return LHS; }
   Init *getRHS() const { return RHS; }
 
   // Fold - If possible, fold this to a simpler init.  Return this if not
   // possible to fold.
-  Init *Fold(Record *CurRec) const override;
+  Init *Fold(Record *CurRec) const;
 
   Init *resolveReferences(Resolver &R) const override;
 
   std::string getAsString() const override;
 };
 
 /// !op (X, Y, Z) - Combine two inits.
 class TernOpInit : public OpInit, public FoldingSetNode {
public:
 
   TernaryOp getOpcode() const { return (TernaryOp)Opc; }
   Init *getLHS() const { return LHS; }
   Init *getMHS() const { return MHS; }
   Init *getRHS() const { return RHS; }
 
   // Fold - If possible, fold this to a simpler init.  Return this if not
   // possible to fold.
-  Init *Fold(Record *CurRec) const override;
+  Init *Fold(Record *CurRec) const;
 
   bool isComplete() const override {
     return LHS->isComplete() && MHS->isComplete() && RHS->isComplete();
   }
 
   Init *resolveReferences(Resolver &R) const override;
 
   std::string getAsString() const override;