Convert Constant->emit() definitions to allow multiple targets to define them.

src/IceOperand.h

Index: src/IceOperand.h
diff --git a/src/IceOperand.h b/src/IceOperand.h
index 3bbd02cb60ba27836d7712522aec9c5dce3da0d5..430a565f418430efaec77976a0a5873d78c53f40 100644
--- a/src/IceOperand.h
+++ b/src/IceOperand.h
@@ -106,9 +106,8 @@ public:
   void emitPoolLabel(Ostream &Str) const {
     Str << ".L$" << getType() << "$" << PoolEntryID;
   }
-  void emit(const Cfg *Func) const override { emit(Func->getContext()); }
-  virtual void emit(GlobalContext *Ctx) const = 0;
-  virtual void emitWithoutDollar(GlobalContext *Ctx) const = 0;
+  void emit(const Cfg *Func) const override { emit(Func->getTarget()); }
+  virtual void emit(TargetLowering *Target) const = 0;
 
   static bool classof(const Operand *Operand) {
     OperandKind Kind = Operand->getKind();
@@ -147,10 +146,7 @@ public:
   }
   PrimType getValue() const { return Value; }
   using Constant::emit;
-  // The target needs to implement this for each ConstantPrimitive
-  // specialization.
-  void emit(GlobalContext *Ctx) const override;
-  void emitWithoutDollar(GlobalContext *Ctx) const override;
+  void emit(TargetLowering *Target) const final;
   using Constant::dump;
   void dump(const Cfg *, Ostream &Str) const override {
     if (ALLOW_DUMP)
@@ -234,9 +230,9 @@ public:
   void setSuppressMangling(bool Value) { SuppressMangling = Value; }
   bool getSuppressMangling() const { return SuppressMangling; }
   using Constant::emit;
+  void emit(TargetLowering *Target) const final;
+  void emitWithoutPrefix(TargetLowering *Target) const;
   using Constant::dump;
-  void emit(GlobalContext *Ctx) const override;
-  void emitWithoutDollar(GlobalContext *Ctx) const override;
   void dump(const Cfg *Func, Ostream &Str) const override;
 
   static bool classof(const Operand *Operand) {
@@ -272,10 +268,8 @@ public:
   }
 
   using Constant::emit;
+  void emit(TargetLowering *Target) const final;
   using Constant::dump;
-  // The target needs to implement this.
-  void emit(GlobalContext *Ctx) const override;
-  void emitWithoutDollar(GlobalContext *Ctx) const override;
   void dump(const Cfg *, Ostream &Str) const override {
     if (ALLOW_DUMP)
       Str << "undef";