feat(core): prevent isolate drop for CLI main worker (#18059)

```
Benchmark 1: deno run -A ../empty.js
  Time (mean ± σ):      20.5 ms ±   0.5 ms    [User: 13.4 ms, System: 5.1 ms]
  Range (min … max):    19.8 ms …  24.0 ms    119 runs

Benchmark 2: target/release/deno run -A ../empty.js
  Time (mean ± σ):      18.8 ms ±   0.3 ms    [User: 13.0 ms, System: 4.9 ms]
  Range (min … max):    18.3 ms …  19.9 ms    129 runs
  ```

---------

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/core/runtime.rs b/core/runtime.rs
index f751138a9..456dbe828 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -93,6 +93,9 @@ pub struct JsRuntime {
   event_loop_middlewares: Vec<Box<OpEventLoopFn>>,
   // Marks if this is considered the top-level runtime. Used only be inspector.
   is_main: bool,
+  // Marks if it's OK to leak the current isolate. Use only by the
+  // CLI main worker.
+  leak_isolate: bool,
 }
 
 pub(crate) struct DynImportModEvaluate {
@@ -305,6 +308,10 @@ pub struct RuntimeOptions {
   /// Describe if this is the main runtime instance, used by debuggers in some
   /// situation - like disconnecting when program finishes running.
   pub is_main: bool,
+
+  /// Whether it is OK to leak the V8 isolate. Only to be used by CLI
+  /// top-level runtime.
+  pub leak_isolate: bool,
 }
 
 #[derive(Copy, Clone, PartialEq, Eq)]
@@ -338,6 +345,16 @@ impl Drop for JsRuntime {
     if let Some(v8_isolate) = self.v8_isolate.as_mut() {
       Self::drop_state_and_module_map(v8_isolate);
     }
+    if self.leak_isolate {
+      if let Some(v8_isolate) = self.v8_isolate.take() {
+        // Clear the GothamState. This allows final env cleanup hooks to run.
+        // Note: that OpState is cloned for every OpCtx, so we can't just drop
+        // one reference to it.
+        let rc_state = self.op_state();
+        rc_state.borrow_mut().clear_state();
+        std::mem::forget(v8_isolate);
+      }
+    }
   }
 }
 
@@ -674,6 +691,7 @@ impl JsRuntime {
       state: state_rc,
       module_map: Some(module_map_rc),
       is_main: options.is_main,
+      leak_isolate: options.leak_isolate,
     };
 
     // Init resources and ops before extensions to make sure they are