Update tonic for VM roll

dart_vm.cc

Index: dart_vm.cc
diff --git a/dart_vm.cc b/dart_vm.cc
index 023dcf10c6f9a30cb4b91c20b6b7269e0025d28b..a56e6823198283381808c394bb43027d1028edaa 100644
--- a/dart_vm.cc
+++ b/dart_vm.cc
@@ -19,6 +19,7 @@ DartVM::Config::Config() {
   interrupt = nullptr;
   unhandled_exception = nullptr;
   shutdown = nullptr;
+  thread_exit = nullptr;
   file_open = nullptr;
   file_read = nullptr;
   file_write = nullptr;
@@ -48,6 +49,7 @@ bool DartVM::Initialize(const Config& config,
                                    config.interrupt,
                                    config.unhandled_exception,
                                    config.shutdown,
+                                   config.thread_exit,
                                    config.file_open,
                                    config.file_read,
                                    config.file_write,