Subzero: Clean up a few areas.

src/IceTypes.h

 //===- subzero/src/IceTypes.h - Primitive ICE types -------------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file declares a few properties of the primitive types allowed
@@ skipping 94 matching lines @@
   return result;
 }
 
 template <typename StreamType>
 inline StreamType &operator<<(StreamType &Str, const Type &Ty) {
   Str << typeString(Ty);
   return Str;
 }
 
 /// Models a type signature for a function.
-/// TODO(kschimpf): Consider using arena memory allocation for
-/// the contents of type signatures.
 class FuncSigType {
-  // FuncSigType(const FuncSigType &Ty) = delete;
   FuncSigType &operator=(const FuncSigType &Ty) = delete;
 public:
   typedef std::vector<Type> ArgListType;
 
   // Creates a function signature type with the given return type.
   // Parameter types should be added using calls to appendArgType.
   FuncSigType() : ReturnType(IceType_void) {}
+  FuncSigType(const FuncSigType &Ty) = default;
 
   void appendArgType(Type ArgType) { ArgList.push_back(ArgType); }
 
   Type getReturnType() const { return ReturnType; }
   void setReturnType(Type NewType) { ReturnType = NewType; }
   SizeT getNumArgs() const { return ArgList.size(); }
   Type getArgType(SizeT Index) const {
     assert(Index < ArgList.size());
     return ArgList[Index];
   }
   const ArgListType &getArgList() const { return ArgList; }
   void dump(Ostream &Stream) const;
 
 private:
   // The return type.
   Type ReturnType;
   // The list of parameters.
   ArgListType ArgList;
 };
 
 inline Ostream &operator<<(Ostream &Stream, const FuncSigType &Sig) {
   Sig.dump(Stream);
   return Stream;
 }
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETYPES_H