feat(runtime): allow adding custom extensions to snapshot (#23569)

This makes `create_runtime_snapshot` more useful for embedders who add
their own extension(s) to the runtime in build scripts.

---------

Signed-off-by: Matt Mastracci <matthew@mastracci.com>
Co-authored-by: Matt Mastracci <matthew@mastracci.com>

cli/build.rs

@@ -346,6 +346,7 @@ fn create_cli_snapshot(snapshot_path: PathBuf) {
   deno_runtime::snapshot::create_runtime_snapshot(
     snapshot_path,
     snapshot_options,
+    vec![],
   );
 }
 

runtime/snapshot.rs

@@ -213,11 +213,13 @@ impl deno_kv::sqlite::SqliteDbHandlerPermissions for Permissions {
 pub fn create_runtime_snapshot(
   snapshot_path: PathBuf,
   snapshot_options: SnapshotOptions,
+  // NOTE: For embedders that wish to add additional extensions to the snapshot
+  custom_extensions: Vec<Extension>,
 ) {
   // NOTE(bartlomieju): ordering is important here, keep it in sync with
   // `runtime/worker.rs`, `runtime/web_worker.rs` and `runtime/snapshot.rs`!
   let fs = std::sync::Arc::new(deno_fs::RealFs);
-  let extensions: Vec<Extension> = vec![
+  let mut extensions: Vec<Extension> = vec![
     deno_webidl::deno_webidl::init_ops_and_esm(),
     deno_console::deno_console::init_ops_and_esm(),
     deno_url::deno_url::init_ops_and_esm(),
@@ -269,6 +271,7 @@ pub fn create_runtime_snapshot(
     ops::bootstrap::deno_bootstrap::init_ops(Some(snapshot_options)),
     ops::web_worker::deno_web_worker::init_ops(),
   ];
+  extensions.extend(custom_extensions);
 
   let output = create_snapshot(
     CreateSnapshotOptions {