Make base set_name take const std:string& instead of std:string

Summary: All the subclasses do that so it causes warnings not to and is dumb because copy constructing std::string is dumb

Reviewed By: kholst

Test Plan: Generate some codes, compile with -Werror


git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665405 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/compiler/cpp/src/parse/t_type.h b/compiler/cpp/src/parse/t_type.h
index b9da4fd..bf8d7fa 100644
--- a/compiler/cpp/src/parse/t_type.h
+++ b/compiler/cpp/src/parse/t_type.h
@@ -29,7 +29,7 @@
  public:
   virtual ~t_type() {}
 
-  virtual void set_name(std::string name) {
+  virtual void set_name(const std::string& name) {
     name_ = name;
   }