Fixes of previous commit on Posix platforms

src/libslic3r/Thread.hpp

@@ -2,6 +2,7 @@
 #define GUI_THREAD_HPP
 
 #include <utility>
+#include <string>
 #include <thread>
 #include <boost/thread.hpp>
 
@@ -16,7 +17,7 @@ inline void set_thread_name(boost::thread &thread, const std::string &thread_nam
 void set_current_thread_name(const char *thread_name);
 inline void set_current_thread_name(const std::string &thread_name) { set_current_thread_name(thread_name.c_str()); }
 
-void std::string get_current_thread_name() const;
+std::string get_current_thread_name();
 
 // To be called somewhere before the TBB threads are spinned for the first time, to
 // give them names recognizible in the debugger.