add function to lib94 to remove all warriors; fix crash on removing last warrior in bench

bench/bench_window.cpp

@@ -320,8 +320,18 @@ void bench_window::on_click_remove_warrior() {
         break;
       }
 
+    if (warriors.size())
       on_click_new_round();
 
+    else {
+      lib94::remove_all_warriors();
+      lib94::clear_address_sets();
+      core.mut.lock();
+      core.clear_all();
+      core.mut.unlock();
+      update_ui();
+    }
+
     delete w;
 
   }

include/lib94/lib94.hpp

@@ -108,6 +108,8 @@ namespace lib94 {
   //with the current time, before the first time you call this.
   bool init_round(const warrior *const *warriors, size_t count, const number_t *offsets, bool shuffle);
 
+  void remove_all_warriors();
+
   //returns the number of warriors who have at least one process
   size_t alive_warrior_count();
 

lib94/core.cpp

@@ -114,6 +114,10 @@ namespace lib94 {
     return true;
   }
 
+  void remove_all_warriors() {
+    alive_warriors.clear();
+  }
+
   size_t alive_warrior_count() {
     return alive_warriors.size();
   }