perf(core, runtime): Further improve startup time (#17860)

This commit further improves startup time by:

- no relying on "JsRuntime::execute_script" for runtime bootstrapping,
this is instead done using V8 APIs directly
- registering error classes during the snapshot time, instead of on
startup

Further improvements can be made, mainly around removing 
"core.initializeAsyncOps()" which takes around 2ms.

This commit should result in ~1ms startup time improvement.

1 files changed, 30 insertions, 5 deletions

diff --git a/core/runtime.rs b/core/runtime.rs
index 9c6b7afea..c028d97c2 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -985,11 +985,36 @@ impl JsRuntime {
   fn init_cbs(&mut self, realm: &JsRealm) {
     let (recv_cb, build_custom_error_cb) = {
       let scope = &mut realm.handle_scope(self.v8_isolate());
-      let recv_cb =
-        Self::eval::<v8::Function>(scope, "Deno.core.opresolve").unwrap();
-      let build_custom_error_cb =
-        Self::eval::<v8::Function>(scope, "Deno.core.buildCustomError")
-          .expect("Deno.core.buildCustomError is undefined in the realm");
+      let context = realm.context();
+      let context_local = v8::Local::new(scope, context);
+      let global = context_local.global(scope);
+      let deno_str = v8::String::new(scope, "Deno").unwrap();
+      let core_str = v8::String::new(scope, "core").unwrap();
+      let opresolve_str = v8::String::new(scope, "opresolve").unwrap();
+      let build_custom_error_str =
+        v8::String::new(scope, "buildCustomError").unwrap();
+
+      let deno_obj: v8::Local<v8::Object> = global
+        .get(scope, deno_str.into())
+        .unwrap()
+        .try_into()
+        .unwrap();
+      let core_obj: v8::Local<v8::Object> = deno_obj
+        .get(scope, core_str.into())
+        .unwrap()
+        .try_into()
+        .unwrap();
+
+      let recv_cb: v8::Local<v8::Function> = core_obj
+        .get(scope, opresolve_str.into())
+        .unwrap()
+        .try_into()
+        .unwrap();
+      let build_custom_error_cb: v8::Local<v8::Function> = core_obj
+        .get(scope, build_custom_error_str.into())
+        .unwrap()
+        .try_into()
+        .unwrap();
       (
         v8::Global::new(scope, recv_cb),
         v8::Global::new(scope, build_custom_error_cb),