goalc: save repl history when the compiler reloads

goalc/compiler/Compiler.cpp

@@ -71,6 +71,10 @@ Compiler::~Compiler() {
   }
 }
 
+void Compiler::save_repl_history() {
+  m_repl->save_history();
+}
+
 void Compiler::print_to_repl(const std::string_view& str) {
   m_repl->print_to_repl(str);
 }

goalc/compiler/Compiler.h

@@ -30,6 +30,7 @@ class Compiler {
  public:
   Compiler(const std::string& user_profile = "#f", std::unique_ptr<ReplWrapper> repl = nullptr);
   ~Compiler();
+  void save_repl_history();
   void print_to_repl(const std::string_view& str);
   std::string get_prompt();
   std::string get_repl_input();

goalc/main.cpp

@@ -127,6 +127,9 @@ int main(int argc, char** argv) {
       if (status == ReplStatus::WANT_RELOAD) {
         fmt::print("Reloading compiler...\n");
         std::lock_guard<std::mutex> lock(compiler_mutex);
+        if (compiler) {
+          compiler->save_repl_history();
+        }
         compiler = std::make_unique<Compiler>(username, std::make_unique<ReplWrapper>());
         status = ReplStatus::OK;
       }