Subzero: Use more "= default;" for ctors and dtors.

src/IceCompileServer.h

 //===- subzero/src/IceCompileServer.h - Compile server ----------*- 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 the compile server. Given a compiler implementation,
@@ skipping 51 matching lines @@
 // Commandline variant of the compile server.
 class CLCompileServer : public CompileServer {
   CLCompileServer() = delete;
   CLCompileServer(const CLCompileServer &) = delete;
   CLCompileServer &operator=(const CLCompileServer &) = delete;
 
 public:
   CLCompileServer(Compiler &Comp, int argc, char **argv)
       : CompileServer(Comp), argc(argc), argv(argv) {}
 
-  ~CLCompileServer() final {}
+  ~CLCompileServer() final = default;
 
   void run() final;
 
 private:
   int argc;
   char **argv;
   std::unique_ptr<GlobalContext> Ctx;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICECOMPILESERVER_H