feat(furc): introduce furvm backend to furc

Closes: #14

furc/src/main.cpp

@@ -1,11 +1,13 @@
 #ifndef LIBFURC
 
 #include "furc/ast/program.hpp"
+#include "furc/back/furvm.hpp"
 #include "furc/front/ir_generator.hpp"
 #include "furc/front/parser.hpp"
 #include "furc/front/post_process.hpp"
 #include "furlang/arena.hpp"
 
+#include <fstream>
 #include <iostream>
 
 int main(void) {
@@ -54,6 +56,9 @@ int main(void) {
             }
         }
 
+        std::ofstream file("./a.fmod", std::ios::binary);
+        furc::back::furvm_generator::generate(mod).serialize(file);
+
         return 0;
     } catch (...) {
         std::cerr << "Caught an exception in main!\n";