feat: add CLI option for (no-)mmap VFS I/O

Some platforms may be fine with memory-mapped I/O and shouldn't suffer
because Windows is silly. The default is still file-based I/O and the
user can be explicit with `--mmap` and `--no-mmap` to indicate their
preference.

bun_extract_file.cpp

@@ -42,6 +42,7 @@ int main(int argc, char *argv[]) {
   std::filesystem::path ggpk_or_steam_dir;
   std::filesystem::path output_dir;
   bool use_regex = false;
+  bool use_mmap = false;
   std::vector<std::string> tail_args;
 
   command = argv[1];
@@ -51,6 +52,12 @@ int main(int argc, char *argv[]) {
     if (argv[argi] == "--regex"sv) {
       use_regex = true;
       ++argi;
+    } else if (argv[argi] == "--mmap"sv) {
+      use_mmap = true;
+      ++argi;
+    } else if (argv[argi] == "--no-mmap"sv) {
+      use_mmap = false;
+      ++argi;
     } else {
       break;
     }
@@ -79,7 +86,7 @@ int main(int argc, char *argv[]) {
 
   std::shared_ptr<GgpkVfs> vfs;
   if (ggpk_or_steam_dir.extension() == ".ggpk") {
-    vfs = open_ggpk(ggpk_or_steam_dir);
+    vfs = open_ggpk(ggpk_or_steam_dir, use_mmap);
   }
 
 #if _WIN32