- Add a _fatal helper function into dart:core, so that we can

runtime/lib/object.cc

Index: runtime/lib/object.cc
===================================================================
--- runtime/lib/object.cc	(revision 43993)
+++ runtime/lib/object.cc	(working copy)
@@ -20,7 +20,20 @@
 DECLARE_FLAG(bool, trace_type_checks);
 DECLARE_FLAG(bool, warn_on_javascript_compatibility);
 
+// Helper function in stacktrace.cc.
+void _printCurrentStacktrace();
 
+DEFINE_NATIVE_ENTRY(DartCore_fatal, 1) {
+  // The core library code entered an unrecoverable state.
+  const Instance& instance = Instance::CheckedHandle(arguments->NativeArgAt(0));
+  const char* msg = instance.ToCString();
+  OS::PrintErr("Fatal error in dart:core\n");
+  _printCurrentStacktrace();
+  FATAL(msg);
+  return Object::null();
+}
+
+
 DEFINE_NATIVE_ENTRY(Object_equals, 1) {
   // Implemented in the flow graph builder.
   UNREACHABLE();