Do not reload isolates if we are in the process of shutting down the VM

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 9be0a0feef65833c58e1ab6d82be332afaae0df2..c20def45467837153a63515762f8a6c5f22139bb 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -1072,8 +1072,9 @@ void Isolate::DoneLoading() {
 
 bool Isolate::CanReload() const {
 #ifndef PRODUCT
-  return (!ServiceIsolate::IsServiceIsolateDescendant(this) &&
-          is_runnable() && !IsReloading() && no_reload_scope_depth_ == 0);
+  return !ServiceIsolate::IsServiceIsolateDescendant(this) &&
+         is_runnable() && !IsReloading() && (no_reload_scope_depth_ == 0) &&
+         IsolateCreationEnabled();
 #else
   return false;
 #endif
@@ -2439,6 +2440,12 @@ void Isolate::EnableIsolateCreation() {
 }
 
 
+bool Isolate::IsolateCreationEnabled() {
+  MonitorLocker ml(isolates_list_monitor_);
+  return creation_enabled_;
+}
+
+
 void Isolate::KillLocked(LibMsgId msg_id) {
   Dart_CObject kill_msg;
   Dart_CObject* list_values[4];