Make fixups reference any constant (allow const float/double pool literals).

src/IceOperand.h

Index: src/IceOperand.h
diff --git a/src/IceOperand.h b/src/IceOperand.h
index 035dc16f9d2fa88fdcfb4a13f43be93e3a2b03bb..6eb5eb9bc526fc82f3ec62fd3d9f8791545e4b87 100644
--- a/src/IceOperand.h
+++ b/src/IceOperand.h
@@ -101,7 +101,9 @@ class Constant : public Operand {
   Constant &operator=(const Constant &) = delete;
 
 public:
-  uint32_t getPoolEntryID() const { return PoolEntryID; }
+  void emitPoolLabel(Ostream &Str) const {
+    Str << ".L$" << getType() << "$" << PoolEntryID;
+  }
   using Operand::dump;
   void emit(const Cfg *Func) const override { emit(Func->getContext()); }
   virtual void emit(GlobalContext *Ctx) const = 0;