VM: Allow configuring use_field_guards on the per-isolate basis and include it into snapshot featur…

runtime/vm/kernel_isolate.cc

Index: runtime/vm/kernel_isolate.cc
diff --git a/runtime/vm/kernel_isolate.cc b/runtime/vm/kernel_isolate.cc
index e10391cdb932a78d8b5af423750ebcdb36eb3229..fe5f542955e7b778010c571123a23afad0338d26 100644
--- a/runtime/vm/kernel_isolate.cc
+++ b/runtime/vm/kernel_isolate.cc
@@ -69,7 +69,12 @@ class RunKernelTask : public ThreadPool::Task {
     }
 
     Dart_IsolateFlags api_flags;

[rmacnak, 2017/02/28 17:52:28]

Add a note that the settings here need to match the setting used during training
as found in //utils/kernel-service/BUILD.gn

[Vyacheslav Egorov (Google), 2017/02/28 21:13:52]

Done.

-    Isolate::FlagsInitialize(&api_flags);
+    api_flags.version = DART_FLAGS_CURRENT_VERSION;
+    api_flags.enable_type_checks = false;
+    api_flags.enable_asserts = false;
+    api_flags.enable_error_on_bad_type = false;
+    api_flags.enable_error_on_bad_override = false;
+    api_flags.use_field_guards = true;
 
     isolate = reinterpret_cast<Isolate*>(create_callback(
         KernelIsolate::kName, NULL, NULL, NULL, &api_flags, NULL, &error));